DE102015215998A1 - Process for the preparation of OCN-pincer ligands from the group of m-terphenyl compounds - Google Patents

Abstract

The present invention relates to a process for the preparation of compounds from the group of m-terphenyls which can be used as OCN-pincer ligands, comprising the process steps a) reacting a compound (A) with a compound (B) to form a coupling product (compound ( B) optionally introducing a protective group into the compound (AB) and c) reacting the compound from a) or b) with a compound (C) to obtain an unsymmetrical m-terphenyl, which is characterized in that at least one the process steps a) or c) is carried out as an electrochemical process step.

Description

The present invention relates to a process for the preparation of compounds from the group of m-terphenyls which can be used as OCN-pincer ligands, comprising the process steps a) reacting a compound (A) with a compound (B) to form a coupling product (compound ( B) optionally introducing a protective group into the compound (AB) and c) reacting the compound from a) or b) with a compound (C) to obtain an unsymmetrical m-terphenyl, which is characterized in that at least one the process steps a) or c) is carried out as an electrochemical process step.

As m-terphenylene usually 1,3-diphenylbenzenes be referred to. Thus, compounds from the group of m-terphenyls contain a 1,3-diphenylbenzylite structure. In the context of the present invention, OCN pinene ligands are understood as meaning compounds which have a 1,3-diphenylbenzene unit, the two outer rings being not an arene but an aniline and a phenol or derivatives derived therefrom. The hydroxyl or amino groups of the aniline or phenol units are each substituted ortho to the arene component.

R⁹ ist definiert als Substituent am C-Atom 1 des Benzolringes, R¹⁰ als Substituent am C-Atom 2, R¹¹ als Substituent am C-Atom 3, R¹² als Substituent am C-Atom 5.Furthermore, in the context of the present invention, the following numbering of the positions in the arsenal component (B) is carried out:

R ⁹ is defined as a substituent on C atom 1 of the benzene ring, R ¹⁰ as a substituent on C atom 2, R ¹¹ as a substituent on C atom 3, R ¹² as a substituent on C atom 5.

In the context of the present invention, the term anilines is understood as meaning aniline derivatives. Thus, the term anilines are understood as meaning those compounds which carry no NH ₂ group but, for example, an NHR group or NR ₂ group.

In the context of the present invention, the term phenols also means phenol derivatives which have no OH group but an OR group.

Schema 1: Darstellung eines OCN-Pincerliganden nach B. Xiao, T.-J. Gong, Z.-J. Liu, J.-H. Liu, D.-F. Luo, J. Xu, L. Liu, J. Am. Chem. Soc. 2011, 133, 9250–9253. So far, only a derivative of an m-terphenyl-OCN-Pincerliganden was synthesized via classical coupling reactions. Anaerobic conditions and exclusion of moisture are also necessary for a successful synthesis by means of a palladium-catalyzed coupling reaction ( B. Xiao, T.-J. Gong, Z.-J. Liu, J.-H. Liu, D.-F. Luo, J. Xu, L. Liu, J. Am. Chem. Soc. 2011, 133, 9250-9253 .). For a successful synthesis, the amine function must be protected from the transition-metal-catalyzed coupling reaction (Scheme 1).

Scheme 1: Representation of an OCN pincer ligand according to B. Xiao, T.-J. Gong, Z.-J. Liu, J.-H. Liu, D.-F. Luo, J. Xu, L. Liu, J. Am. Chem. Soc. 2011, 133, 9250-9253.

A major disadvantage of the above cross-coupling methods of phenolic and aniline derivatives with arenes is the need for dry solvents and exclusion of air during the coupling reaction. In classical cross-coupling methods, the protection of the hydroxyl and amine functionalities is necessary in most cases. Furthermore, starting functionalities are introduced into the substrates used for a regioselective cross-coupling which occur after the actual coupling reaction as environmentally problematic reaction waste. The tolerance of functional groups is often limited by the reagents used, so that in particular less substituted derivatives can be used. During the reaction often occur toxic by-products, which must be separated from the desired product consuming and expensive to dispose of. Dwindling resources make the preparation of ligand systems by palladium-catalyzed cross-coupling or chemical oxidants very expensive.

Electrochemical processes for the cross-coupling of phenolic and aniline derivatives with arenes to form m-terphenyl compounds are not yet known.

The object of the present invention was therefore to provide a simple process for the preparation of OCN pincer ligands from the group of m-terphenyl compounds, which avoids one or more disadvantages of the prior art.

Surprisingly, it has been found that this object can be achieved by carrying out at least one of the process steps as an electrochemical process step in a process which comprises two process steps of the reaction.

The present invention therefore provides a process for the preparation of compounds from the group of m-terphenyls which can be used as OCN-pincer ligands as defined in the claims, comprising the process steps a) reacting a compound (A) with a compound ( B) to a coupling product (compound (AB)), b) optionally introducing a protective group into the compound (AB) and c) reacting the compound from a) or b) with a compound (C) to obtain an unsymmetrical m-terphenyl, which is characterized in that at least one of the process steps a) or c) is carried out as an electrochemical process step.

wie nachfolgend definiert. Likewise provided by the present invention are compounds of the formula (ABC)

as defined below.

In addition, the present invention is the use of the compounds of the invention as a ligand for the preparation of metal-ligand catalyst systems.

The inventive method has the advantage that the partial or complete implementation by means of electrochemical process steps, the production of unsymmetrical m-terphenyl compounds is substantially simplified, since a moisture exclusion or compliance with anaerobic reaction conditions need not be guaranteed. Among other things, this leads to less effort in carrying out the method.

The implementation of a process step or several process steps as electrochemical process steps also has the advantage that the formation of undesirable by-products can be significantly reduced.

By electrochemical cross-coupling eliminates the use of expensive and toxic catalysts, such as the introduction of activating leaving functionalities before the coupling reaction (inventive step a)).

Depending on the embodiment of the method according to the invention, the method allows for the first time the direct synthesis of asymmetric compounds with low synthetic effort and high tolerance of functional groups in the substrates used.

Furthermore, in the method according to the invention, the use of chemical oxidizing agents can be dispensed with, in part or preferably completely. In this way, the risk of the formation of by-products or the contamination of the compounds by residues of the oxidizing agent is avoided.

The inventive method also has the advantage that a large variety of different m-Terphenylverbindungen can be represented, which were not accessible or only with great effort by the known from the prior art methods.

In particular, the process according to the invention has the advantage that it can be used to prepare the m-terphenyl compounds (m-terphenyls) according to the invention.

The inventive method, the compounds of the invention and their use are described below by way of example, without the invention being limited to these exemplary embodiments. Given below, ranges, general formulas, or classes of compounds are intended to encompass not only the corresponding regions or groups of compounds explicitly mentioned, but also all sub-regions and sub-groups of compounds obtained by removing individual values (ranges) or compounds can be. If documents are cited in the context of the present description, their content, in particular with regard to the matters referred to, should form part of the disclosure content of the present invention. If the following information is given as a percentage, it is, unless otherwise stated, in Vol%. If mean values are given below, this is the number average, unless stated otherwise. Are below material properties such. As viscosities or the like, it is, unless otherwise stated, the material properties at 25 ° C.

(ABC) umfassend die Verfahrensschritte

• a) Umsetzen einer Verbindung (A)
  
  mit einer Verbindung (B)
  
  unter Erhalt einer Verbindung (AB)
  
• b) optional Schützen der X-Gruppe der Verbindung (AB) mit einer Schutzgruppe unter Erhalt einer geschützten Verbindung (AB), und
• c) Umsetzen der Verbindung (AB) aus a) oder b) mit einer Verbindung (C)
  
  mit X und Y = -OR‘ oder -NR’‘R‘‘‘ und der Maßgabe, wenn X = -OR‘ ist, Y = -NR’‘R‘‘‘ ist und wenn Y = -OR‘ ist, X = -NR’‘R‘‘‘ ist, R‘, R‘‘ und R‘‘‘ gleich oder verschieden ausgewählt aus der Gruppe umfassend H, Kohlenwasserstoffreste, Heteroatome aufweisende Kohlenwasserstoffreste und Schutzgruppenfunktionen, vorzugsweise ausgewählt aus den Schutzgruppen umfassend tert-Butyloxycarbonyl, Methyloxycarbonyl, Benzyloxycarbonyl, Phenyloxycarbonyl, Acetyl, Trifluoracetyl, Benzoyl, Sulfonyl und Sulfenyl, wobei die Reste R‘‘ und R‘‘‘ auch über eine kovalente Bindung verknüpft sein können, und R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹ und R¹² unabhängig voneinander ausgewählt sind aus der Gruppe enthaltend Wasserstoff, Kohlenwasserstoffreste und Heteroatome aufweisende Kohlenwasserstoffreste, vorzugsweise enthaltend Wasserstoff, (C₁-C₁₂)-Alkyl, O-(C₁-C₁₂)-Alkyl, -N[(C₁-C₁₂)-Alkyl]₂, -NH(C₁-C₁₂)-Alkyl, (C₆-C₂₀)-Aryl, O-(C₆-C₂₀)-Aryl, -OH und Halogen, besonders vorzugsweise enthaltend Wasserstoff, (C₁-C₁₂)-Alkyl, O-(C₁-C₁₂)-Alkyl, -N[(C₁-C₁₂)-Alkyl]₂, -OH und Halogen, ganz besonders bevorzugt enthaltend Wasserstoff, (C₁-C₁₂)-Alkyl, O-(C₁-C₁₂)-Alkyl, -N[(C₁-C₁₂)-Alkyl]₂, -OH, Chlor und Iod, sehr besonders bevorzugt enthaltend Wasserstoff, (C₁-C₁₂)-Alkyl, O-(C₁-C₁₂)-Alkyl, -OH, Chlor und Iod, wobei benachbarte Reste aus der Gruppe der Reste R¹ bis R¹² über eine kovalente Bindung verbunden sein können, dadurch gekennzeichnet, dass mindestens einer der Verfahrensschritte a) oder c) als elektrochemischer Verfahrensschritt durchgeführt wird.

The process according to the invention for the preparation of compounds from the group of the m-terphenyls of the formula (ABC)

(ABC) comprising the process steps

• a) Reacting a compound (A)
  
  with a compound (B)
  
  to obtain a compound (AB)
  
• b) optionally protecting the X group of the compound (AB) with a protecting group to give a protected compound (AB), and
• c) reacting the compound (AB) from a) or b) with a compound (C)
  
  with X and Y = -OR 'or -NR''R''' and the proviso if X = -OR ', Y = -NR''R''' and if Y = -OR ', X = -NR''R ''', R ', R''andR''' identically or differently selected from the group consisting of H, hydrocarbon radicals, heteroatom-containing hydrocarbon radicals and protective group functions, preferably selected from the protective groups comprising tert-butyloxycarbonyl, methyloxycarbonyl, benzyloxycarbonyl, phenyloxycarbonyl, acetyl, trifluoroacetyl, benzoyl , Sulfonyl and sulfenyl, where the radicals R '' and R '''can also be linked via a covalent bond, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ^{12 are} independently selected from the group consisting of hydrogen, hydrocarbon radicals and hydrocarbon radicals containing heteroatoms, preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -Alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , -NH (C ₁ -C ₁₂ ) -alkyl, (C ₆ -C ₂₀ ) -aryl, O- (C ₆ -C ₂₀ ) - Aryl, -OH and halogen, particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , - O H and halogen, very particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , -OH, Chlorine and iodine, very particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -OH, chlorine and iodine, where adjacent radicals from the group of radicals R ¹ to R ^{12 can be} connected via a covalent bond, characterized in that at least one of the process steps a) or c) is carried out as an electrochemical process step.

Neighboring radicals in the context of the present invention are those radicals which are bonded to directly adjacent C atoms. In the case of compound (A) z. B. the radicals R ¹ and R ² . Examples of such radicals are, for example, -O- (CH ₂ ) _z -O- with z = 1 to 5, preferably 1 to 3, preferably 1,

In the context of the present invention, halogen is understood to mean fluorine, chlorine, bromine or iodine, in particular fluorine, chlorine and bromine. In the context of the present invention, the term alkyl is understood to mean a linear or branched hydrocarbon radical in which optionally one or more hydrogen atoms, preferably by halogen atoms or hydroxyl or alk (yl) oxy groups, may be substituted. Aryl means in the context of the present invention, aromatic hydrocarbon radicals, such as. Phenyl (C ₆ H ₅ -), naphthyl (C ₁₀ H ₇ -), anthryl (C ₁₄ H ₉ -), preferably phenyl, in which optionally one or more hydrogen atoms, preferably by alkyl or alk ( yl) oxy groups, may be substituted.

In the context of the invention, the term - (C ₁ -C ₁₂ ) -alkyl comprises straight-chain and branched alkyl groups. Preferably, these are unsubstituted straight-chain or branched - (C ₁ -C ₈ ) -alkyl and most preferably - (C ₁ -C ₆ ) -alkyl groups. Examples of - (C ₁ -C ₁₂ ) -alkyl groups are, in particular, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2- Methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3 Methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl -, 1-Propylbutyl, n-octyl, 2-ethylhexyl, 2-propylheptyl, nonyl, decyl, or dodecyl. The radicals "(C ₁ -C ₁₂ ) -alkyl and O- (C ₁ -C ₁₂ ) -alkyl" may each be unsubstituted or substituted by one or more identical or different radicals selected from (C ₃ -C ₁₂ ) -Cycloalkyl, (C ₃ -C ₁₂ ) -heterocycloalkyl, (C ₆ -C ₂₀ ) -aryl, fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl.

The explanations concerning the expression - (C ₁ -C ₁₂ ) -alkyl also apply to the alkyl groups in -O- (C ₁ -C ₁₂ ) -alkyl, ie in - (C ₁ -C ₁₂ ) -alkoxy. These are preferably unsubstituted straight-chain or branched - (C ₁ -C ₆ ) -alkoxy groups

The term - (C ₆ -C ₂₀ ) -aryl comprises in the context of the present invention mono- or polycyclic aromatic hydrocarbon radicals. These have 6 to 20 ring atoms, particularly preferably 6 to 14 ring atoms, in particular 6 to 10 ring atoms, on. Aryl is preferably - (C ₆ -C ₁₀ ) -aryl and - (C ₆ -C ₁₀ ) -aryl (C ₆ -C ₁₀ ) -aryl. Aryl is especially phenyl, naphthyl, indenyl, fluorenyl, anthracenyl, phenanthrenyl, naphthacenyl, chrysenyl, pyrenyl, coronenyl. In particular, aryl is phenyl, naphthyl and antracenyl.

Substituted - (C ₆ -C ₂₀ ) -aryl groups may, depending on the ring size, have one or more (eg 1, 2, 3, 4 or 5) substituents. These substituents are preferably independently selected from -H, - (C ₁ -C ₁₂ ) -alkyl, -O- (C ₁ -C ₁₂ ) -alkyl, -O- (C ₆ -C ₂₀ ) -aryl, - ( C ₆ -C ₂₀ ) -aryl, -halogen (such as Cl, F, Br, I), -COO- (C ₁ -C ₁₂ ) -alkyl, -CONH- (C ₁ -C ₁₂ ) -alkyl, - ( C ₆ -C ₂₀ ) -aryl-CON [(C ₁ -C ₁₂ ) -alkyl] ₂ , -CO- (C ₁ -C ₁₂ ) -alkyl, -CO- (C ₆ -C ₂₀ ) -aryl, COOH, -OH, -SO ₃ H; -SO ₃ Na, -NO ₂ , -CN, -NH ₂ , -N [(C ₁ -C ₁₂ ) -alkyl]

It may be advantageous to isolate the coupling product from step a), ie the compound (AB), before it is fed to process step c).

It is inventively preferred in the process steps a), b) and c) recover unreacted starting materials, which preferably takes place by distillation. The recovered educts can be recycled to the corresponding process steps a), b) or c) as feedstock.

• aa) eine Mischung mindestens eines Lösemittels und mindestens eines Leitsalzes erzeugt wird,
• bb) zu dieser Mischung die umzusetzenden Verbindungen gegeben werden, wobei die Verbindung (A) bzw. (C) im molaren Unterschuss bezogen auf die Verbindung (B) bzw. (AB) zugegeben wird,
• cc) Einbringen von mindestens zwei Elektroden in die unter bb) erhaltene Reaktionslösung und Anlegen einer Spannung an die Elektroden,
• dd) Umsetzen der Komponenten zu den entsprechenden Kupplungsprodukten,
• ee) Abschalten der Spannung, und ggf.
• ff) Isolierung und/oder Aufreinigung des Umsetzungsproduktes.

Preferably, the electrochemical process step (s) is carried out such that

• aa) a mixture of at least one solvent and at least one conducting salt is produced,
• bb) the compounds to be reacted are added to this mixture, the compound (A) or (C) being added in molar excess relative to the compound (B) or (AB),
• cc) introducing at least two electrodes into the reaction solution obtained under bb) and applying a voltage to the electrodes,
• dd) reacting the components to the corresponding coupling products,
• ee) switching off the voltage, and possibly
• ff) Isolation and / or purification of the reaction product.

• a1) Mischen mindestens eines Lösemittels und eines Leitsalzes,
• a2) Zugabe der Verbindungen (A) und (B) zur Mischung aus a1), wobei die Verbindung (B) in einem molaren Überschuss bezogen auf die Verbindung (A) zugegeben wird,
• a3) Einbringen von mindestens zwei Elektroden in die Reaktionslösung und Anlegen einer Spannung an die Elektroden
• a4) Kupplung der Verbindung (A) an die Verbindung (B) unter Erhalt eines Kupplungsprodukt (Verbindung (AB)),
• a5) Abschalten der Spannung, Abtrennen und ggf. Aufreinigung des Kupplungsproduktes,
• b1) optional Schützen der Amino- oder Hydroxy-Gruppe Kupplungsprodukts mit einer Schutzgruppe unter Erhalt eines geschützten Kupplungsprodukts und
• c1) Mischen des Kupplungsproduktes aus Schritt a5) oder des geschützten aus Schritt b1) mit einer Reaktionslösung aus mindestens einem Lösemittel und einem darin enthaltenen Leitsalz,
• c2) Zugabe der Verbindung (C), wobei das Kupplungsprodukt in einem molaren Überschuss bezogen auf die Verbindung (C) in der Reaktionslösung vorliegt,
• c3) Einbringen von mindestens zwei Elektroden in die Reaktionslösung und Anlegen einer Spannung an die Elektroden,
• c4) Kupplung der Verbindung (C) an das Kupplungsprodukt (Verbindung (AB)) zu einem m-Terphenyl (Verbindung (ABC)),
• c5) Abschalten der Spannung und ggf.
• c6) Isolierung und/oder Aufarbeitung des m-Terphenyls (Verbindung (ABC)).

If both process steps a) and c) are carried out as electrochemical process steps, the process according to the invention is preferably carried out such that it comprises the process steps:

• a1) mixing at least one solvent and one conducting salt,
• a2) adding the compounds (A) and (B) to the mixture of a1), wherein the compound (B) is added in a molar excess based on the compound (A),
• a3) introducing at least two electrodes into the reaction solution and applying a voltage to the electrodes
• a4) coupling the compound (A) to the compound (B) to obtain a coupling product (compound (AB)),
• a5) switching off the voltage, separating and if necessary cleaning the coupling product,
• b1) optionally protecting the amino or hydroxy group coupling product with a protecting group to give a protected coupling product and
• c1) mixing the coupling product from step a5) or the protected from step b1) with a reaction solution of at least one solvent and a conductive salt contained therein,
• c2) adding the compound (C), wherein the coupling product is present in a molar excess based on the compound (C) in the reaction solution,
• c3) introducing at least two electrodes into the reaction solution and applying a voltage to the electrodes,
• c4) coupling the compound (C) to the coupling product (compound (AB)) to an m-terphenyl (compound (ABC)),
• c5) switching off the voltage and possibly
• c6) Isolation and / or work-up of the m-terphenyl (compound (ABC)).

The electrochemical process steps may, for. Based on that of a.) A. Kirste, B. Elsler, G. Schnakenburg, SR Waldvogel, J. Am. Chem. Soc. 2012, 134, 3571-3576 , b.) A. Kirste, S. Hayashi, G. Schnakenburg, IM Malkowsky, F. Stecker, A. Fischer, T. Fuchigami, SR Waldvogel, Chem. Eur. J. 2011, 17, 14164-14169 , c.) Elsler, D. Schollmeyer, KM Dyballa, R. Franke, SR Waldvogel, Angew. Chem. Int. Ed. 2014, 53, 5210-5213 , and d.) A. Kirste, M. Nieger, IM Malkowsky, F. Stecker, A. Fischer, SR Waldvogel, Chem. Eur. J. 2009, 15, 2273-2277 described methods for the electrochemical coupling of carbon-carbon bonds, performed.

The electrochemical process steps can be carried out in all suitable, known from the prior art electrolysis cells. In the method according to the invention, a flange cell, a beaker cell or a screening cell is preferably used. Such cells are described in the literature and the first two glass cells can, e.g. under this name at HWS Labortechnik Mainz.

The cell has at least two electrodes. Commercially available electrodes can be used as electrodes. As anodes can preferably z. B. BDD (0.015 mm boron-doped diamond on silicon or 0.05 mm boron-doped diamond on niobium), platinum, isostatic graphite or glassy carbon electrodes can be used. The cathodes used are preferably BDD, nickel mesh or glassy carbon electrodes. Such BDD electrodes (boron-doped diamond on a support, such as niobium or silicon) are z. B. under the name DIACHEM at the company Condias GmbH Itzehoe available. The remaining electrodes are available from major chemical and material suppliers such as Goodfellow or Aldrich.

The electrochemical process step or the electrochemical process steps are preferably carried out in the presence of a solvent. The solvent used is preferably a solvent from the group of acetonitrile, propylene carbonate, methyl carbonate, nitromethane, ethylene glycol dimethyl ether, methanesulfonic acid, benzene, toluene, water, methanol, ethanol, propanol, isopropanol, halogenated solvents or halogenated or non-halogenated acids or mixtures thereof.

Preferred solvents are a carboxylic acid, preferably formic acid, a fluorinated carboxylic acid or a fluorinated alcohol, preferably trifluoroacetic acid or 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), preferably 1,1,1,3 , 3,3-hexafluoro-2-propanol used.

Particularly preferred solvents are methanol, formic acid trifluoroacetic acid, hexafluoroisopropanol or mixtures thereof, preferably methanol, hexafluoroisopropanol or mixtures thereof, and more preferably hexafluoroisopropanol (1,1,1,3,3,3-hexafluoro-2-propanol).

The electrochemical process step or the electrochemical process steps are preferably carried out in the presence of at least one conducting salt, preference being given to using as guide salts those which are selected from the group of tetra (C ₁ -C ₆ -alkyl) -ammonium or 1,3- Di (C ₁ -C ₆ alkyl) imidazolium salts, with the proviso that the alkyl groups may be halogen-substituted, in particular with fluorine-substituted. Preferably, such conductive salts are used which have counterions which are selected from the group comprising arsenate, sulfate, hydrogen sulfate, alkyl sulfate, alkyl phosphate, perchlorate, fluoride, aryl sulfate, hexafluorophosphate and tetrafluoroborate. Preferred conducting salts are those from the group of quaternary ammonium borates, Ammoniumfluoralkylphosphate, Ammoniumfluoralkylarsenate, Ammoniumtrifluor-methylsulfonates, ammonium bis (fluoromethansulfon) imides, Ammoniumtris- (fluoromethansulfonyl) methides, methyltributylammonium methylsulfate, methyltriethylammonium methylsulfate, tetrabutylammonium hexafluorophosphate, tetraethylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate or lithium hexafluorophosphate. Particular preference is given to using methyltriethylammonium methylsulfate or Bu ₃ NMe ⁺ MeOSO ₃ ^- (methyltributylammonium methylsulfate), very particularly preferably methyltributylammonium methylsulfate, as the conductive salt.

The conductive salt is preferably used in a concentration of 0.001 to 10 mol / L, preferably 0.01 to 1 mol / L, particularly preferably from 0.075 to 0.125 mol / L and most preferably from 0.09 mol / L based on the reaction mixture ,

In the process according to the invention, preference is given in each case to using so much compound A or compound C that the concentration in the reaction mixture is from 0.001 to 5 mol / l, preferably from 0.05 to 0.5 mol / l, preferably from 0.1 to 0.3 mol / L and particularly preferably 0.15 mol / L.

The electrochemical process step or the electrochemical process steps are preferably carried out at room temperature or elevated temperature. The electrochemical process step or the electrochemical process steps are preferably carried out at a temperature in the electrolysis cell in the range from 25 to 80.degree. C., preferably from 35 to 70.degree. C. and preferably from 45 to 55.degree.

The electrochemical process step or the electrochemical process steps are preferably carried out galvanostatically.

When carrying out the electrochemical process step or the electrochemical process steps, the current intensity is preferably selected such that the current density is from 1 to 10 mA / cm ² , preferably from 2 to 5.5 mA / cm ² , preferably from 2.5 to 3 mA / cm ² and preferably 2.8 mA / cm ² . For carrying out the electrochemical process step or the electrochemical process steps, a (clamping) voltage is preferably applied between the electrodes in the range from 2 to 10 V, preferably 2.5 to 7.5 V and preferably from 3 to 6 V.

It may be advantageous when so much compound (B) and compound (A) is employed that the molar ratio of compound (B) to compound (A) is in the range of 1.5: 1 to 6: 1, preferably in the Range 2: 1 to 3: 1.

The molar ratio of the compound (AB) to the compound (C) is preferably in the range of 1.5: 1 to 6: 1, preferably in the range of 2: 1 to 3: 1.

Particularly preferably, the proportions are chosen so that in step a) the molar ratio of compound (B) to compound (A) in the range of 1.5 to 1 to 6: 1, preferably in the range 2: 1 to 3: 1 and in step b) the molar ratio of the compound (AB) to the compound (C) is in the range from 1.5: 1 to 6: 1, preferably in the range from 2: 1 to 3: 1.

As compounds of the formula (A), those are preferably used in which X is -OR 'with R' as defined above, preferably. Preference is given to using those compounds of the formula (A) in which X is OH, ie phenols whose hydroxyl group is not protected.

Preferred compounds of the formula (C) are those in which Y = -NR''R '''withR''andR''' as defined above, where, if at least one of the radicals R '' or R ''''is a protecting group, this is preferably selected from the group containing tert-butyloxycarbonyl, methyloxycarbonyl, benzyloxycarbonyl, phenyloxycarbonyl, acetyl, trifluoroacetyl, benzoyl, sulfonyl, sulfenyl and pivaloyl, preferably containing acetyl, trifluoroacetyl, benzoyl and pivaloyl, and more preferably containing acetyl and trifluoroacetyl. Very particular preference is given to using a compound (C) in which Y = -NH ₂ .

Preferred compounds of the formula (B) are those in which the radicals R ¹⁰ and R ^{12 are} identical and are preferably hydrogen.

Schema 2: Elektrochemische Durchführung des Verfahrensschrittes c): Synthese ungeschützter und N-geschützter OCN-Pincerliganden. MTBS: Bu₃NMe MeOSO₃. PG: Schutzgruppe. In the following, the implementation of the method according to the invention is shown by way of example by way of a few reaction schemes, with both method steps a) and c) being carried out in each case as electrochemical method steps. The radicals R ¹ to R ⁴ used in the schemes are as defined above.

Scheme 2: Electrochemical performance of step c): Synthesis of unprotected and N-protected OCN pincer ligands. MTBS: Bu ₃ NMe MeOSO ₃ . PG: protecting group.

Schema 3: Elektrochemische Durchführung des Verfahrensschritt a); Synthese der Verbindung AB. (MTBS: Bu₃NMe MeOSO₃). The Coupling of a Phenol to a 1,3-Disubstituted Arene in the First Reaction Step (Scheme 3) Results in a Coupling Product (Compound AB)

Scheme 3: Electrochemical performance of process step a); Synthesis of the compound AB. (MTBS: Bu ₃ NMe MeOSO ₃ ).

Schema 4: Elektrochemische Synthese ungeschützter OCN-Pincerliganden. MTBS: Bu₃NMe MeOSO₃. By reaction, particularly anodic reaction, of the compound (AB) with an unprotected aniline derivative, unprotected OCN pincer ligands are obtained (Scheme 4).

Scheme 4: Electrochemical synthesis of unprotected OCN pincer ligands. MTBS: Bu ₃ NMe MeOSO ₃ .

Such compounds are not previously described in the classical way or accessible only with high synthetic effort.

It can be advantageous if, between process step a) and process step c), a process step b) is carried out in which the functional group X is protected by a suitable protective group. Such a method step is particularly advantageous if both method steps a) and c) are carried out as electrochemical process steps.

Process step b) can be carried out in such a way that the coupling product from process step a) is reacted with a suitable compound before or after working up.

If it is intended to use as compounds (A) or (C) those which have protected functional groups X and Y, respectively, in which R 'or R "is not hydrogen, such compounds can be prepared in a simple manner by introducing appropriate protective groups from compounds (A) and (C), respectively, in which R 'or R "is hydrogen.

Protecting groups and their introduction are known to the person skilled in the art and can be taken from the usual technical literature (see also: PGM Wuts, TW Greene "Green's Protective Groups in Organic Synthesis", fourth edition, 2007, John Wiley and Sons; Hoboken, New Jersey ).

The process according to the invention is preferably carried out in such a way that the reaction in the electrochemical process steps, preferably the entire reaction, is carried out without the use of organic oxidizing agents.

(ABC) mit X, Y und R¹ bis R¹² wie oben definiert, hergestellt werden. Mit dem erfindungsgemäßen Verfahren können insbesondere die erfindungsgemäßen Verbindungen der Formel (ABC) hergestellt werden. With the aid of the process according to the invention, a large variety of different m-terphenyl compounds, in particular those of the formula (ABC)

(ABC) with X, Y and R ¹ to R ¹² as defined above. In particular, the novel compounds of the formula (ABC) can be prepared by the process according to the invention.

ABC mit X und Y sowie den Resten R¹ bis R¹² wie vorstehend definiert, mit Ausnahme der Verbindung der Formel (3)

(3). The compounds of the invention satisfy the formula (ABC)

ABC with X and Y and the radicals R ¹ to R ¹² as defined above, with the exception of the compound of the formula (3)

(3).

Preferably, in the compounds of the invention of the formula ABC X = -OH and Y = -NH ₂ or -NR''R '''withR''= acetyl and R''' = H.

genügen.In the compounds of the formula ABC, the radicals R ¹⁰ and R ^{12 are} preferably hydrogens. The radicals R ⁹ and R ¹¹ are preferably not a hydrogen, the radicals R ⁹ and R ¹¹ are preferably methyl or methoxy, most preferably methyl groups. Particularly preferred compounds ABC according to the invention are those of the formula (1) or (2)

suffice.

The compounds of the invention can be used as a ligand for the preparation of metal-ligand catalyst systems.

The present invention will be described with reference to 1 to 4 described by way of example, without the invention, the scope of which will become apparent from the entire description and the claims to be limited to the embodiments shown in the figures. In the 1 to 4 are schematic drawings of cells, as they can be used in the process according to the invention and as used in particular in the following examples, mapped.

1 schematically shows a screening cell. In 2 are with 1 the BDD electrodes, with 2 a teflon lid, with 3 a teflon cup and with 4 a stirring magnet.

2 schematically shows a flange (glass). In 2 are with 1 a stainless steel rod with attached nickel mesh cathode, with 2 a teflon stopper, with 3 a cooling jacket (glass), with 4 a screw clamp, with 5 a BDD electrode, with 6 an EPDM gasket and with 7 a stirring magnet.

3 schematically shows a beaker cell small (glass). In 3 are with 1 a stainless steel rod for contacting, with 2 a teflon stopper, with 3 a cell outlet / port, e.g. B. for a Dimroth cooler, with 4 Electrode holders (stainless steel), with 5 Glassy carbon electrodes and with 6 a stirring magnet.

4 schematically shows a beaker cell large (glass). In 4 are with 1 the BDD electrodes, with 2 the connections for contacting, with 3 the glass jacket, with 4 a stirring magnet, with 5 a cell outlet / connection, eg for a Dimroth cooler and with 6 an electrically conductive contact (stainless steel foil).

In the examples given below, the present invention is described by way of example, without the invention, the scope of application of which is apparent from the entire description and the claims, to be limited to the embodiments mentioned in the examples.

Experimental part

General methods

Chromatography (GC / GCMS)

Preparative liquid chromatography for the separation of mixtures was carried out using silica gel 60 M (0.040-0.063 mm) from MACHERY-NAGEL GMBH & CO. KG. KG, Düren at a maximum pressure of 2 bar. All eluents used (ethyl acetate, technical grade, cyclohexane, technical grade) were previously purified by distillation on a rotary evaporator. Thin-layer chromatography (TLC) was carried out on PSC precast plates Kieselgel 60 F ₂₅₄ from MERCK KGaA, Darmstadt. Detection of the various substances was carried out initially under UV light and then by staining with Cer-Molybdatophosphorsäure reagent (5.6 g molybdophosphoric acid, 2.2 g of cerium (IV) sulfate tetrahydrate and 13.3 g of concentrated sulfuric acid to 200 mL Water) and then heated by a hot air dryer.

Gas chromatography (GC / GCMS)

The gas chromatographic investigations (GC) of product mixtures and pure substances was carried out with the aid of the gas chromatograph GC-2010 from Shimadzu, Japan. It is attached to a quartz capillary column HP-5 from Agilent Technologies, USA (length: 30 m, internal diameter: 0.25 mm, film thickness of the covalently bonded stationary phase: 0.25 μm, carrier gas: hydrogen, injector temperature: 250 ° C, detector temperature : 310 ° C, program: "hard" method: 50 ° C start temperature for 1 min, heating rate: 15 ° C / min, 290 ° C final temperature for 8 min). Gas chromatographic mass spectra (GCMS) of product mixtures and pure substances were recorded using the gas chromatograph GC-2010 combined with the mass detector GCMS-QP2010 from Shimadzu, Japan. It is attached to a quartz capillary column HP-1 from Agilent Technologies, USA (length: 30 m, internal diameter: 0.25 mm, film thickness of the covalently bonded stationary phase: 0.25 μm, carrier gas: hydrogen, injector temperature: 250 ° C, detector temperature : 310 ° C, program: "hard" method: 50 ° C start temperature for 1 min, heating rate: 15 ° C / min, 290 ° C final temperature for 8 min, GCMS: temperature of the ion source: 200 ° C).

Mass spectrometry

All electrospray ionization (ESI +) measurements were carried out on a QTof Ultima 3 from Waters Micromasses, Milford, Massachusetts. EI mass spectra and the high-resolution EI spectra were measured on a MAT 95 XL sector field device from Thermo Finnigan, Bremen.

NMR spectroscopy

The NMR spectroscopic investigations were carried out on multicore resonance spectrometers of the type AC 300 or AV II 400 from Bruker, Analytical Messtechnik, Karlsruhe. The solvent used was CDCl3. The ¹ H and ¹³ C spectra were calibrated according to the residual content of non-deuterated solvent according to the NMR Solvent Data Chart from Cambridge Isotopes Laboratories, USA. The assignment of the ¹ H and ¹³ C signals was carried out in part by means of H, H-COZY, H, H-NOESY, H, C-HSQC and H, C-HMBC spectra. The chemical shifts are given as δ values in ppm. The following abbreviations were used for the multiplicities of the NMR signals: s (singlet), bs (broad singlet), d (doublet), t (triplet), q (quartet), m (multiplet), dd (doublet of doublet), dt (doublet of triplet), tq (triplet of quartet). All coupling constants J were given in terms of the number of bound bonds in hertz (Hz). The numbering specified for the signal assignment corresponds to the numbering specified in the formula diagrams, which does not necessarily have to comply with the IUPAC nomenclature.

Crystal structure

The single-crystal structure analyzes were carried out at the Institute of Organic Chemistry of the Johannes Gutenberg University Mainz on a device of the type IPDS 2T of the company STOE & Cie GmbH, Darmstadt.

melting points

The relevant melting points were measured with the aid of the melting point determination device SG 2000 from HW5, Mainz and were taken over uncorrected.

General working instructions

AAV1: Electrochemical cross-coupling in L cells

5 mmol of the species A or A 'to be oxidized (deficiency component) were mixed with a 2-3-fold excess (10-15 mmol) of the coupling partner B or AB in 33 mL of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) or 33 mL (HFIP with 18% by volume of methanol (MeOH) based on the sum of HFIP and MeOH) in an undivided flanged cell with BDD anode and nickel-mesh cathode. The conductive salt used was Bu ₃ NMe ⁺ MeOSO ₃ ^- (MTBS) with a concentration of 0.09 M. The electrolysis was carried out by galvanostasis. The outer jacket of the electrolysis cell was tempered via a thermostat to about 10 ° C, while the reaction mixture was stirred and heated to 50 ° C by means of an oil bath. After the end of the electrolysis, the cell contents were transferred to a 50 ml round-bottomed flask and the solvent was removed under reduced pressure on a rotary evaporator at 50 ° C., 200-70 mbar. Mineralization products and the conductive salt contained was separated by elution with ethyl acetate (300 mL) over 50 g of silica gel 60. Unreacted starting material was recovered by short path distillation at Kugelrohrdestille (100 ° C, 10 ^-3 mbar). The resulting reaction products were separated by column chromatography as indicated. Electrode material: Anode: BDD (15 μm diamond layer) on silicon substrate Cathode: nickel net Electrolysis conditions: Temperature: 50 ° C Current density: 2.8 mA / cm ² Amount of charge: 2-4 F on the deficit component Clamping voltage: 3-6 v

AAV2: Electrochemical cross-coupling in a beaker cell with stacked electrode arrangement

120 mmol of the species A to be oxidized (deficiency component) were mixed with a 2-3-fold excess (240-360 mmol) of the coupling partner B in 750 mL of 1,1,1,3,3,3-hexafluoroisopropanol or 750 mL (HFIP with 18vol% MeOH, based on the sum of HFIP and MeOH) in a beaker cell with a stacked arrangement of 10 BDD electrodes (5 times anode, 5 times cathode) implemented. The conductive salt used was MTBS with a concentration of 0.09 M. The electrolysis was carried out by galvanostasis. Evaporating HFIP was redistilled by means of a Dimroth condenser and fed to electrolysis while the reaction mixture was stirred and heated to 50 ° C with an oil bath. After the end of the electrolysis, the cell contents were transferred to a 1 L round-bottomed flask and the solvent was removed under reduced pressure on a rotary evaporator at 50 ° C., 200-70 mbar. Mineralization products and the conductive salt contained were separated by elution with ethyl acetate (2 L) over 300 g of silica gel 60. Unreacted starting material was recovered by short path distillation at Kugelrohrdestille (100 ° C, 10 ^-3 mbar). Electrode material: Anode: 5 times BDD on niobium Cathode: 5 times BDD on niobium Electrolysis conditions: Temperature: 50 ° C Current density: 2.8 mA / cm ² Amount of charge: 2-4 F based on the deficit component Clamping voltage: 3-6 v

AAV3: Electrochemical cross-coupling in a beaker cell

3.8 mmol of the species A to be oxidized (deficiency component) were mixed with a 2-3-fold excess (7.6-11 mmol) of the coupling partner B in 25 mL of 1,1,1,3,3,3-hexafluoroisopropanol or 25 mL (HFIP with 18vol% MeOH, based on the sum of HFIP and MeOH) in a beaker cell reacted on glassy carbon electrodes. The conductive salt used was MTBS with a concentration of 0.09 M. The electrolysis was carried out by galvanostasis. Evaporating HFIP was redistilled by means of a Dimroth condenser and fed to electrolysis while the reaction mixture was stirred and heated to 50 ° C with an oil bath. At the end of the electrolysis, the cell contents were transferred to a 100 mL round bottom flask and the solvent removed under reduced pressure Rotary evaporator at 50 ° C, 200-70 mbar. Mineralization products and the conductive salt contained were separated by elution with ethyl acetate (300 mL) over 50 g of silica gel 60. Unreacted starting material was recovered by short path distillation at Kugelrohrdestille (100 ° C, 10 ^-3 mbar). Electrode material: Anode: Glassy carbon Cathode: Glassy carbon Electrolysis conditions: Temperature: 50 ° C Current density: 2.8 mA / cm ² Amount of charge: 2-4 F on the deficit component Clamping voltage: 3-6 v

AAV4: Electrochemical cross-coupling in a screening cell

0.76 mmol of the species A to be oxidized (deficit component) were mixed with a 2-3-fold excess (1.52-2.28 mmol) of the coupling partner B in 5 mL of 1,1,1,3,3,3-hexafluoroisopropanol or 5 mL (HFIP with 18 vol% MeOH based on the sum of HFIP and MeOH) were reacted in a beaker cell on glassy carbon electrodes. The conductive salt used was MTBS with a concentration of 0.09 M. The electrolysis was carried out by galvanostasis. The reaction mixture was placed in a stainless steel block, stirred by means of a stirrer and kept at 50 ° C. After the end of the electrolysis, the cell contents were transferred to a 50 ml round-bottomed flask and the solvent was removed under reduced pressure on a rotary evaporator at 50 ° C., 200-70 mbar. Mineralization products and the conductive salt contained were separated by elution with ethyl acetate (150 mL) over 20 g of silica gel 60. Unreacted starting material was recovered by short path distillation at Kugelrohrdestille (100 ° C, 10 ^-3 mbar). Electrode material: Anode: BDD (50 μm) on niobium Cathode: BDD (50 μm) on niobium Electrolysis conditions: Temperature: 50 ° C Current density: 2.8 mA / cm ² Amount of charge: 2-4 F based on the deficit component Clamping voltage: 3-6 v

Two-stage pincersynthesis:

Example 1:

2 ', 4'-dimethyl-2-hydroxy-4-iodo-5-methoxy

Ausbeute: 208 mg (0,6 mmol, 15%)
GC (Methode hart, HP-5): t_R = 14,39 min
R_f (Cy:EE = 9:1) = 0,43
¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 2.15 (s, 3H), 2.38 (s, 3H), 3.80 (s, 3H), 6.58 (s, 1H), 7.11 (s, 1H), 7.11 (s, 1H), 7.16 (s, 1H), 7.42 (s, 1H).
¹³C-NMR (101 MHz, CDCl₃) δ [ppm] = 19.78, 21.31, 57.13, 85.05, 112.66, 126.03, 127.43, 128.47, 130.21, 131.72, 132.25, 137.09, 138.88, 147.42, 152.37.
HRMS (ESI, pos. mode): m/z für C₁₅H₁₅IO₂ (M+Na⁺):
berechnet: 377,0014; gefunden: 377,0005The electrolysis was carried out according to AAV3 with 950 mg (3.8 mmol, 1.0 equiv.) Of 3-iodo-4-methoxyphenol and 1.17 g (11 mmol, 3.0 equiv.) Of m-xylene. The current density was 2.8 mA / cm ² , the charge amount 3 F per 4-methoxy-3-methylphenol (Q = 1095 C). The product was purified by column chromatography on silica gel 60 with a gradient 99: 1, then 95: 5 (CH: EE). The product was obtained as a brown oil.

Yield: 208 mg (0.6 mmol, 15%)
GC (hard method, HP-5): t _R = 14.39 min
R _f (Cy: EE = 9: 1) = 0.43
¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 2.15 (s, 3H), 2.38 (s, 3H), 3.80 (s, 3H), 6.58 (s, 1H), 7.11 (s, 1H) , 7.11 (s, 1H), 7.16 (s, 1H), 7.42 (s, 1H).
¹³ C-NMR (101 MHz, CDCl ₃₎ δ [ppm] = 19.78, 21:31, 57.13, 85.05, 112.66, 126.03, 127.43, 128.47, 130.21, 131.72, 132.25, 137.09, 138.88, 147.42, 152.37.
HRMS (ESI, pos mode): m / z for C ₁₅ H ₁₅ IO ₂ (M + Na ⁺ ):
calculated: 377,0014; found: 377,0005

Example 2:

2-Amino-3-chloro-2 '', 4-dihydroxy-4 '' - iodo-5 '' - methoxy-2 ', 4', 5-trimethyl [1,1 '; 5'1' '] terphenyl

Ausbeute: 39 mg (0,07 mmol, 10%)
GC (Methode methode1, HP-5): t_R = 33,48 min
¹H-NMR (400 MHz, Methanol-D₄) δ [ppm] = 2.16 (s, 3H), 2.18 (s, 3H), 2.33 (s, 3H), 3.81 (s, 3H), 6.64 (d, J = 0.9 Hz, 1H), 6.71 (s, 1H), 7.12–7.00 (m, 3H).
¹³C-NMR (101 MHz, Methanol-D₄) δ [ppm] = 16.17, 20.11, 21.21, 57.53, 93.64, 108.88, 114.60, 116.71, 119.57, 127.23, 130.72, 131.37, 131.46, 131.73, 132.73, 135.98, 137.64, 138.35, 140.64, 146.97, 152.31, 153.69.The electrolysis was carried out in accordance with AAV4 with 120 mg (0.76 mmol, 1.0 equiv.) Of 2-chloro-3-hydroxy-4-methylaniline and 535 mg (1.53 mmol, 2.0 equiv.) 2 ', 4' Dimethyl 2-hydroxy-4-iodo-5-methoxybiphenyl (from Example 1). The current density was 2.8 mA / cm ² , the charge amount 2 F per 2-chloro-3-hydroxy-4-methylaniline (Q = 146.2 C). Excess starting material was removed by Kugelrohr distillation (100 ° C., 10 ^-3 mbar). The product was purified by column chromatography on silica gel 60 with a gradient 7: 3, then 2: 1, then 1: 1 (CH: EE). The product was obtained as a dark red oil.

Yield: 39 mg (0.07 mmol, 10%)
GC (method method1, HP-5): t _R = 33.48 min
¹ H-NMR (400 MHz, methanol-D ₄ ) δ [ppm] = 2.16 (s, 3H), 2.18 (s, 3H), 2.33 (s, 3H), 3.81 (s, 3H), 6.64 (d, J = 0.9 Hz, 1H), 6.71 (s, 1H), 7.12-7.00 (m, 3H).
¹³ C-NMR (101 MHz, methanol-D ₄ ) δ [ppm] = 16.17, 20.11, 21.21, 57.53, 93.64, 108.88, 114.60, 116.71, 119.57, 127.23, 130.72, 131.37, 131.46, 131.73, 132.73, 135.98, 137.64, 138.35, 140.64, 146.97, 152.31, 153.69.

Example 3:

5-N-acetamido-6- (4,6-dimethyl-2'-hydroxy-3'-iodo-4'-methoxy-biphenyl-3-yl) benzo-1,3-dioxole

Ausbeute: 34 mg (0,06 mmol, 6%)
GC (Methode methode1, HP-5): t_R = 35,22 min
¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 2.02 (s, 3H), 2.14 (s, 3H), 2.34 (s, 3H), 3.85 (s, 3H), 5.90 (s, 2H), 6.37 (s, 1H), 6.68 (s, 1H), 7.01 (s, 1H), 7.03 (s, 1H), 7.07 (s, 1H), 7.11 (s, 1H), 7.40 (s, 1H), 7.80 (s, 1H).
¹³C-NMR (101 MHz, CDCl₃) δ [ppm] = 20.13, 21.27, 24.69, 57.01, 84.29, 99.62, 101.56, 102.48, 113.48, 122.94, 126.54, 129.37, 129.74, 130.97, 133.87, 134.49, 136.05, 138.19, 140.43, 143.16, 143.40, 147.94, 154.95, 167.81.The electrolysis was carried out according to AAV4 with 137 mg (0.76 mmol, 1.0 equiv) of 5-N-acetaminobenzo-1,3-dioxole and 535 mg (1.53 mmol, 2.0 equiv.) Of 2 ', 4'-dimethyl- 2-hydroxy-4-iodo-5-methoxybiphenyl (from Example 1). The current density was 2.8 mA / cm ² , the charge amount 2 F per 5-N-acetaminobenzo-1,3-dioxole (Q = 146.2 C). Excess starting material was removed by Kugelrohr distillation (100 ° C., 10 ^-3 mbar). The product was purified by column chromatography on silica gel 60 with a gradient 7: 3, then 2: 1, then 1: 1 (CH: EE). The product was obtained as a yellow oil.

Yield: 34 mg (0.06 mmol, 6%)
GC (method method1, HP-5): t _R = 35.22 min
¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 2.02 (s, 3H), 2.14 (s, 3H), 2.34 (s, 3H), 3.85 (s, 3H), 5.90 (s, 2H) , 6.37 (s, 1H), 6.68 (s, 1H), 7.01 (s, 1H), 7.03 (s, 1H), 7.07 (s, 1H), 7.11 (s, 1H), 7.40 (s, 1H), 7.80 (s, 1H).
¹³ C-NMR (101 MHz, CDCl ₃₎ δ [ppm] = 20:13, 21:27, 24.69, 57.01, 84.29, 99.62, 101.56, 102.48, 113.48, 122.94, 126.54, 129.37, 129.74, 130.97, 133.87, 134.49, 136.05, 138.19, 140.43, 143.16, 143.40, 147.94, 154.95, 167.81.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• B. Xiao, T.-J. Gong, Z.-J. Liu, J.-H. Liu, D.-F. Luo, J. Xu, L. Liu, J. Am. Chem. Soc. 2011, 133, 9250-9253 [0006]
• A. Kirste, B. Elsler, G. Schnakenburg, SR Waldvogel, J. Am. Chem. Soc. 2012, 134, 3571-3576 [0033]
• A. Kirste, S. Hayashi, G. Schnakenburg, IM Malkowsky, F. Stecker, A. Fischer, T. Fuchigami, SR Waldvogel, Chem. Eur. J. 2011, 17, 14164-14169 [0033]
• Elsler, D. Schollmeyer, KM Dyballa, R. Franke, SR Waldvogel, Angew. Chem. Int. Ed. 2014, 53, 5210-5213 [0033]
• A. Kirste, M. Nieger, IM Malkowsky, F. Stecker, A. Fischer, SR Waldvogel, Chem. Eur. J. 2009, 15, 2273-2277 [0033]
• PGM Wuts, TW Greene "Green's Protective Groups in Organic Synthesis", fourth edition, 2007, John Wiley and Sons; Hoboken, New Jersey [0058]

Claims (17)

Process for the preparation of compounds from the group of m-terphenyls of the formula (ABC)

comprising the process steps a) reacting a compound (A)

with a compound (B)

to obtain a compound (AB)

b) optionally protecting the X group of the compound (AB) with a protecting group to give a protected compound (AB), and c) reacting the compound (AB) from a) or b) with a compound (C)

with X and Y = -OR 'or -NR''R''' and the proviso if X = -OR ', Y = -NR''R''' and if Y = -OR ', X = -NR''R ''', R ', R''andR''' identically or differently selected from the group consisting of H, hydrocarbon radicals, heteroatom-containing hydrocarbon radicals and protective group functions, preferably selected from the protective groups comprising tert-butyloxycarbonyl, methyloxycarbonyl, benzyloxycarbonyl, phenyloxycarbonyl, acetyl, trifluoroacetyl, benzoyl , Sulfonyl and sulfenyl, where the radicals R '' and R '''can also be linked via a covalent bond, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ^{12 are} independently selected from the group consisting of hydrogen, hydrocarbon radicals and hydrocarbon radicals containing heteroatoms, preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -Alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , -NH (C ₁ -C ₁₂ ) -alkyl, (C ₆ -C ₂₀ ) -aryl, O- (C ₆ -C ₂₀ ) - Aryl, -OH and halogen, particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , - O H and halogen, very particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -N [(C ₁ -C ₁₂ ) -alkyl] ₂ , -OH, Chlorine and iodine, very particularly preferably containing hydrogen, (C ₁ -C ₁₂ ) -alkyl, O- (C ₁ -C ₁₂ ) -alkyl, -OH, chlorine and iodine, where adjacent radicals from the group of radicals R ¹ to R ^{12 can be} connected via a covalent bond, characterized in that at least one of the process steps a) or c) is carried out as an electrochemical process step. A method according to claim 1, characterized in that both process steps a) and c) are carried out as electrochemical process steps. Process according to claim 1 or 2, characterized in that the electrochemical process step is carried out such that aa) a mixture of at least one solvent and at least one conducting salt is produced, bb) the compounds to be reacted are added to this mixture, the compound (A) or (C) in a molar excess based on the compound (B) or (AB) is added, cc) introducing at least two electrodes in the reaction solution obtained under bb) and applying a voltage to the electrodes, dd) reacting the components ee) switching off the voltage, and if necessary ff) isolation and / or purification of the reaction product. Method according to one of claims 1 to 3, characterized in that the molar ratio of the compound (B) to the compound (A) in the range of 1.5: 1 to 6: 1, preferably from 2: 1 to 3: 1. Method according to one of claims 1 to 4, characterized in that the molar ratio of the compound (AB) to the compound (C) in the range of 1.5: 1 to 6: 1, preferably from 2: 1 to 3: 1. Method according to one of claims 1 to 5, characterized in that a compound of formula (A) is used, wherein X = -OH. Method according to one of claims 1 to 6, characterized in that a compound of formula (C) is used, wherein Y = -NR''R ''', with R''= protective group function. Method according to one of claims 1 to 7, characterized in that a compound of formula (B) is used, the radicals R ¹⁰ and R ^{12 are} identical and are preferably hydrogen. Method according to one of claims 1 to 8, characterized in that the electrochemical process step is carried out in the presence of a solvent and as a solvent solvent from the group of acetonitrile, propylene carbonate, methyl carbonate, nitromethane, ethylene glycol dimethyl ether, methanesulfonic acid, benzene, toluene, water, methanol , Ethanol, propanol, isopropanol, halogenated solvents or halogenated or non-halogenated acids or mixtures thereof. A method according to claim 9, characterized in that the solvent used is methanol, formic acid trifluoroacetic acid, hexafluoroisopropanol or mixtures thereof, preferably methanol, hexafluoroisopropanol or mixtures thereof, and preferably hexafluoroisopropanol. Method according to one of claims 1 to 10, characterized in that the reaction is carried out without the use of organic oxidizing agents. Method according to one of claims 1 to 11, characterized in that the electrochemical process step is carried out in the presence of at least one conductive salt, being used as conductive salts are those selected from the group of tetra (C ₁ -C ₆ alkyl) -ammonium - or (1,3-di (C ₁ -C ₆ alkyl) imidazolium salts, with the proviso that the alkyl groups may be halogen-substituted. A method according to claim 12, characterized in that the counterions of the conductive salts are selected from the group comprising arsenate, sulfate, hydrogen sulfate, alkyl sulfate, alkyl phosphate, perchlorate, fluoride, aryl sulfate, hexafluorophosphate and tetrafluoroborate.  A process according to claim 12 or 13, wherein the conductive salt is a salt selected from the group consisting of quaternary ammonium borates, ammonium fluoroalkyl phosphates, ammonium fluoroalkyl arsenates, ammonium trifluoromethyl sulfonates, ammonium bis (fluoromethanesulfone) imides, ammonium tris (fluoromethanesulfonyl) methides, methyltributylammonium methylsulfate, methyltriethylammonium methylsulfate, tetrabutylammonium hexafluorophosphate, tetraethylammonium tetrafluoroborate, Lithium hexafluorophosphate or tetraethylammonium tetrafluoroborate, preferably Methyltriethylammoniummethylsulfat or Bu3NMe + MeOSO3- (Methyltributylammoniummethylsulfat) and particularly preferably Methyltributylammoniummethylsulfat is used. Compounds of the formula (ABC)

with X and Y and the radicals R ¹ to R ¹² as defined in any one of the preceding claims, with the exception of the compound of the formula (3)

Compound according to Claim 15, characterized in that it has the formula (1) or (2)

enough.  Use of a compound according to claim 15 or 16 as a ligand for the preparation of metal-ligand catalyst systems.

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