RU2160271C1 - Method of preparing 1-dialkylamine-2,3-fullerene [60] alumacyclopropanes - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: described is method of preparing 1- dialkylamine-2,3-fullerene [60]alumacyclopropanes of formula I:

wherein n is 1-6, R is C₂H₅,C₄H₉ and C₆₀ is allotropic modification of carbon by reacting fullerene [60] with excessive amount of dialkylaminealuminium dichloride and activated magnesium in the presence of titanocene dichloride in argon atmosphere under normal conditions in solvents for 12-16 hours. EFFECT: new organoaluminium compounds. 8 cl, 1 tbl

Description

где n = 1-6; R=C₂H₅, C₄H₉; C₆₀-аллотропная модификация углерода.The invention relates to methods for producing new organoaluminum compounds, in particular, to a method for producing 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes of the general formula (1)

where n = 1-6; R = C ₂ H ₅ , C ₄ H ₉ ; C ₆₀ allotropic modification of carbon.

 The proposed fullerene-containing cyclic organoaluminum compounds can be used in organic and organometallic synthesis, and functionalization products (1) are of interest as extractants, sorbents, additives, physiologically active substances.

Известный способ не позволяет получать 1-диалкиламин-2,3-фуллерен[60] алюмациклопропаны (1).The known method (Dzhemilev U.M., Ibragimov A.G., Zolotarev A.P., Halilov L.M., Musloukhov R.R. Izv. AN. Series: Chemistry - 1992, N 2, p. 386-391 ) obtaining polycyclic organoaluminum compounds, for example, 1-ethylaluminatricyclo [5.2.1.0 ^2,6 ) -decane (2) by reaction of AlEt ₃ with norbornene, taken in equimolar amounts, in the presence of 3-5 mol% of a Cp ₂ ZrCl ₂ catalyst at room temperature in hydrocarbon solvents for 12 to 14 hours according to the scheme:

The known method does not allow to obtain 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes (1).

Известный способ не позволяет получать 1-диалкиламин-2,3-фуллерен[60] алюмациклопропаны (1).The known method (U.M. Dzhemilev, A.G. Ibragimov, L.O. Khafizova, L.M. Khalilov, Yu.V. Vasiliev, R.F. Tuktarov, Yu.V. Tomilov, O.M. Nefedov Izv. AN Ser.chem. 1999, N 3, 572-574) for the preparation of 1-ethyl-2,3-fullerenalumumacyclopentanes (3) by the reaction of AlEt ₃ with [60] fullerene taken in the molar ratio [Al]: C ₆₀ = 300: 1, in the presence of 2 mol.% Cp ₂ ZrCl ₂ at 22-23 ^o C for 36 hours according to the scheme:

The known method does not allow to obtain 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes (1).

 Thus, in the literature there is no information on the synthesis of 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes (1).

 A method for the synthesis of 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes (1) is proposed.

The essence of the method consists in the interaction of fullerene [60] (a new modification of carbon) with an excess of dialkylamine aluminum dichloride of the general form R ₂ N-AlCl ₂ , where R = C ₂ H ₅ , C ₄ H ₉ , and activated magnesium, taken in a molar ratio of C ₆₀ : R ₂ N-AlCl ₂ : Mg = 1: (50-150) :( 30-50), preferably 1: 100: 40, in the presence of a titanocenedichloride catalyst (Cp ₂ TiCl ₂ ) in an amount of 0.5-1.5 mol . % with respect to R ₂ N-AlCl ₂ , preferably 1 mol.%, in an argon atmosphere at a temperature of 20-22 ^o C and normal pressure for 12 to 16 hours, preferably 14 hours in a mixture of solvents toluene-THF. The yield of cyclic organoaluminum compounds (1), determined by the products of hydrolysis using HPLC, is 66 - 82%.

Диалкиламиналюминийдихлорид (R₂N-AlCl₂) и магний берут в избытке по отношению к фуллерену [60] с целью включения в молекулу C₆₀ максимального количества алюмациклопропановых фрагментов. Снижение количества R₂N-AlCl₂ и магния по отношению к C₆₀, например, C₆₀:R₂N-AlCl₂:Mg=1:30:15, приводит к уменьшению выхода целевых продуктов, а также к снижению вводимых в молекулу C₆₀ алюмациклопропановых заместителей. Изменение соотношения исходных реагентов в сторону увеличения содержания R₂N-AlCl₂ или Mg по отношению к C₆₀, например, C₆₀: R₂N-AlCl₂:Mg=1:200:75, не приводит к существенному повышению выхода целевых продуктов, а также увеличению количества вводимых в молекулу фуллерена алюмациклопропановых фрагментов.The reaction proceeds according to the scheme:

Dialkylaminaluminium dichloride (R ₂ N-AlCl ₂ ) and magnesium are taken in excess with respect to fullerene [60] in order to include the maximum amount of aluminacyclopropane fragments into the C ₆₀ molecule. A decrease in the amount of R ₂ N-AlCl ₂ and magnesium relative to C ₆₀ , for example, C ₆₀ : R ₂ N-AlCl ₂ : Mg = 1: 30: 15, leads to a decrease in the yield of the target products, as well as to a decrease in the amount introduced into the molecule C ₆₀ aluminacyclopropane substituents. The change in the ratio of the starting reagents in the direction of increasing the content of R ₂ N-AlCl ₂ or Mg relative to C ₆₀ , for example, C ₆₀ : R ₂ N-AlCl ₂ : Mg = 1: 200: 75, does not significantly increase the yield of the target products , as well as an increase in the number of aluminacyclopropane fragments introduced into the fullerene molecule.

1-Dialkylamine-2,3-fullerenalumacyclopropanes (1) are formed only with the participation of R ₂ N-AlCl ₂ , magnesium and the catalyst Cp ₂ TiCl ₂ . In the presence of other aluminum compounds (e.g. EtAlCl ₂ , AlBu ₃ ⁱ , Et ₂ AlCl, i-Bu ₂ AlH, i-Bu ₂ AlCl) or another catalyst (e.g. Zr (acac) ₄ , TiCl ₄ , Ni (acac) ₂ , PdCl ₂ ) target products (1) are not formed. When Mg, acting as an acceptor of chlorine ions, was replaced by other metals, for example, Ca, Na, and Li, the yield of the target products decreased.

Carrying out the specified reaction in the presence of a catalyst Cp ₂ TiCl ₂ more than 1.5 mol. % does not lead to a significant increase in the yield of target products. The use of the catalyst Cp ₂ TiCl ₂ less than 0.5 mol.% Reduces the yield of 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes, which is possibly associated with a decrease in catalytically active centers in the reaction mass. The experiments were carried out at room temperature. At a higher temperature, for example 50 ^o C, there is no significant increase in the yield of the target products, at a lower temperature, for example 0 ^o C, the reaction rate decreases.

Significant differences of the proposed method:
1. The proposed method is based on the use of dialkylaminaluminium dichlorides (R ₂ N-AlCl ₂ ) and Mg as starting reagents, and Cp ₂ TiCl ₂ as a catalyst. In the known method, AlEt ₃ and a Cp ₂ ZrCl ₂ catalyst are used. In addition, if in the known method, 1-ethyl-2,3-fullerene [60] aluminacyclopentanes (3) are formed during the reaction, then in the proposed method 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes (1) are formed the synthesis of which is not described in the literature.

The method is illustrated by the following examples.
Example 1. In a 50 ml glass reactor mounted on a magnetic stirrer in an argon atmosphere at a temperature of ~ 0 ^° C, 0.05 mmol of fullerene [60], 25 ml of dry toluene and 10 ml of THF, 5 mmol (C ₂ H ₅ ) are placed ₂ N-AlCl ₂ , 2 g-at. Mg (powder) and a Cp ₂ TiCl ₂ catalyst in an amount of 0.05 mmol (1 mol% with respect to (C ₂ H ₅ ) ₂ N-AlCl ₂ ), the temperature was raised to room temperature (20 - 22 ^o C) and stirred 14 hours. Obtain 1-diethylamine-2,3-fullerene [60] aluminacyclopropanes of the general formula (1) with the number of aluminacyclopropane fragments from 1 to 6 with a total yield of 74%. The yield was determined by HPLC of hydrolysis products (4).

Продукты гидролиза (4) и дейтеролиза (5) необходимо сразу же выделять из раствора для их анализа спектральными методами, что связано с высокой реакционной способностью (4) и (5) по отношению к исходным растворителям и кислороду воздуха (A.D. Darwish, A.K. Abdul-Sada, G.J. Langley, H.W. Kroto, R. Taylor, D.R.M. Walton. J. Chem. Soc. Perkin Trans. 2, 1995, 2359-2365).

The products of hydrolysis (4) and deuterolysis (5) must be immediately isolated from the solution for their analysis by spectral methods, which is associated with the high reactivity of (4) and (5) with respect to the starting solvents and air oxygen (AD Darwish, AK Abdul- Sada, GJ Langley, HW Kroto, R. Taylor, DRM Walton. J. Chem. Soc. Perkin Trans. 2, 1995, 2359-2365).

Мультиплетные сигналы в области 3,10-4,80, 6,45-6,90.Spectral characteristics (4) and (5):
1H NMR spectrum (δ, ppm, CDCl ₃ ) of polyhydrofullerenes (4):

Multiplet signals in the field of 3.10-4.80, 6.45-6.90.

IR spectrum (ν, cm ^-1 ) of polyhydrofullerenes (4): 2915, 2852 (CH). Mass spectrum of negative polydeuterofullerenes ions (5): mass lines with m / z values from 724 [C ₆₀ D ₂ ] to 744 [C ₆₀ D ₁₂ ].

 Other examples confirming the method are given in the table.

The reactions were carried out at room temperature (20–22 ^° C) in a toluene – THF solvent mixture, which was associated with the good solubility of the starting fullerene [60] in toluene and the good solubility of MgCl ₂ (by-product) in THF. The temperature increase is impractical, since there is no significant increase in the yield of the target products. At lower temperatures, the reaction rate decreases.

Claims (1)

The method of obtaining 1-dialkylamine-2,3-fullerene [60] aluminacyclopropanes of the General formula

where n = 1 to 6;
R is C ₂ H ₅ , C ₄ H ₉ ;
C ₆₀ - allotropic modification of carbon,
characterized in that fullerene [60] interacts with an excess of dialkylaminaluminium dichloride of the form R ₂ N-AlCl ₂ , where R is C ₂ H ₅ , C ₄ H ₉ , and activated magnesium, taken in a molar ratio of C ₆₀ : R ₂ N-AlCl ₂ : Mg = 1: (50 - 150): (30 - 50) in the presence of a catalyst titanocene dichloride (Cp ₂ TiCl ₂ ) in an amount of 0.5 - 1.5 mol.% In relation to dialkylaminaluminium dichloride in an argon atmosphere under normal conditions in the presence of a mixture of toluene and tetrahydrofuran as solvents for 12 to 16 hours

Images