RU2532925C2 - Method of obtaining pyridinates of 1-fluoro(chloro)-3-alkyl(aryl)borolanes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining pyridinates of 1-fluoro(chloro)-3-alkyl(aryl)borolanes of general formula

(1), where R=Bu, X=F (a); R=Hex, X=F (b); R=Hex, X=Cl (c); R=Bn, X=Cl (d). The method includes the interaction of unsaturated compounds, selected from the group of hex-1-ene, oct-1-ene or allylbenzene, with triethylaluminium (AlEt₃) in the presence of a catalyst (Cp₂ZrCl₂) in a ratio of 10:12:0.5 in hexane in an atmosphere of inert gas with mixing for 7 h, addition of boron trifluoride etherate (BF₃·Et₂O) or boron chloride (BCl₃) and pyridine in a double with respect to AlEt₃ amount, following mixing at room temperature for 30-60 min.

EFFECT: obtained compounds can be applied as components of catalytic systems in processes of oligo- and polymerisation of olefin, diene and acetylene hydrocarbons, as well as in fine organic and organometallic synthesis.

1 ex

Description

The present invention relates to the field of organoboron synthesis, specifically to a method for producing 1-fluoro (chloro) -3-alkyl (aryl) borolanes pyridinates of the general formula (I):

, где R=Bu, X=F (а); R=Hex, X=F (б);

where R = Bu, X = F (a); R = Hex, X = F (b);

R = Hex, X = Cl (c); R = Bn, X = Cl (g)

The proposed compounds can be used as components of catalytic systems in the processes of oligo- and polymerization of olefin, diene and acetylene hydrocarbons, as well as in fine organic and organometallic syntheses ([1], E. You-Xian Chen. Cocotalysts for metal-catalyzed polymerization: activators, activation processes, and structure-activity relationships // Chem. Rev., 2000, 100, 1391-1434).

A known method ([2], Eisch JJ, Shafii B., Odom JD, Rheingold AL Aromatic stabilization of the triarylborirene ring system by tricoordinate boron and facile ring opening with tetracoordinate boron // JACS, 1990, 112, 1847-1853) for the preparation of pyridine complexes of triarylborienes (2) by the reaction of magnesium acetylenide and dimesitylborane fluoride followed by photoirradiation and pyridine addition according to the scheme:

In a known manner, pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes (1) cannot be obtained.

A method is known ([3], Eisch JJ Forty years of Umpolung in organometallic chemistry: from carbanionic nucleophiles to metallic electrophiles // J. Organometal. Chem. 1995, 500, 101-115) for the preparation of pyridinate of trimesitylboriene (5) by the interaction of pyridine with trimesitylboriene ( 4) obtained by haloborinating dimesityl acetylene with aryldibromoborane and subsequent cyclization (3) under the action of lithium, according to the scheme

The known method cannot be obtained pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes (1).

The known method ([4], Eisch JJ, Galle JE, Kozima S. Physical and chemical consequences of cyclic conjugation in boracyclopolyenes. The antiaromatic character of pentaarylboroles // J. Am. Chem. Soc., 1986, 108, 379-385) for the preparation of pentaarylborole pyridinates (6) by reacting pyridine with 2,3,4,5-tetraarylborols obtained by transmetallation of 1,1-dimethyl-2,3,4,5-tetraaryl stanols with R'BX ₂ according to the scheme

The known method does not allow to obtain pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes (1).

Thus, in the literature there is no information on the synthesis of 1-fluoro (chloro) -3-alkyl (aryl) borolanes pyridinates (1).

A new method is proposed for preparing 1-fluoro (chloro) -3-alkyl (aryl) borolanes pyridinates (1).

The essence of the method consists in the interaction in an inert gas atmosphere of unsaturated compounds selected from the series hex-1-en, oct-1-en, allylbenzene with triethylaluminum (AlEt ₃ ) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ), taken in a molar ratio unsaturated compound: AlEt ₃ : Cp ₂ ZrCl ₂ = 10: 12: 0.5, at room temperature (~ 20 ° C) for 7 h in hexane, followed by cooling of the reaction mixture to -10 ° C, adding BF ₃ · Et ₂ O or BCl ₃ and pyridine in twice the amount with respect to Et ₃ Al. Stirred at room temperature for 30-60 minutes, preferably 45 minutes The desired product was isolated by vacuum distillation. The yield of 1-fluoro (chloro) -3-alkyl (aryl) borolanes (1) pyridinates isolated by distillation under reduced pressure is 75-85%. The reaction proceeds according to the scheme:

1-fluoro (chloro) -3-alkyl (aryl) borolanes pyridinates (1) are formed only with the participation of unsaturated compounds selected from the series hex-1-ene, oct-1-ene, allylbenzene, triethylaluminium, a catalyst of zirconacenedichloride and BF ₃ Et ₂ O or BCl ₃ . In the presence of other boron derivatives (e.g. Et ₂ BCl, EtBCl ₂ , C ₆ F ₅ BF ₂ ), other organoaluminum compounds (e.g. Et ₂ AlCl, EtAlCl ₂ , i-Bu ₃ Al), other unsaturated compounds (e.g. allens , acetylenes) or another catalyst (for example, Cp ₂ TiCl ₂ , Pd (acac) ₂ , NiCl ₂ , Ni (acac) ₂ , CoCl ₂ ) the target products (1) are not formed.

The addition of pyridine and boron halide was carried out at a temperature of -10 ° C. Lowering the temperature, for example, to -30 ° C does not affect the yield of the target products, however, insufficient cooling (for example, 10 ° C) leads to a significant decrease in the yield of the target products.

Significant differences of the proposed method

In the proposed method, unsaturated compounds selected from the series (hex-1-ene, oct-1-ene, allylbenzene), triethylaluminum, catalyst zirconacenedichloride, BF ₃ · Et ₂ O or BCl ₃ and pyridine are used as starting compounds. The proposed method allows to obtain pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes. In the known method, diarylacetylenes, lithium, dimethyltin dichloride, diethyl ether, pyridine, boron chloride or dihaloarylboranes are used as starting compounds. In a known manner, pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes (1) cannot be obtained.

The method is illustrated by the following examples:

EXAMPLE 1. In a glass reactor in an argon atmosphere, 1.12 g (10 mmol) oct-1-ene, 1.92 ml (12 mmol) of 92% AlEt ₃ , 0.15 g (0.5 mmol) Cp ₂ are successively placed at 0 ° C with stirring. ZrCl ₂ , 10 ml of hexane and stirred for 7 hours at room temperature. After cooling the reaction mass to −10 ° C., 3.04 ml (24 mmol) of BF ₃ · Et ₂ O and 1.93 ml (24 mmol) of pyridine are added dropwise. Stirred at room temperature for 45 minutes. The solvent was evaporated and the reaction mixture was distilled in vacuo. Get 1-fluoro-3-hexylborolane pyridinate (1b) in 80% yield.

1-Fluoro-3-hexylborolane Py (1b): b.p. 122 ° C (15 mmHg). ¹ H NMR spectrum (δ, ppm, THF-d ₈ ): 0.09 (t, 1H, C ² H _a , J = 12 Hz), 0.39-0.46 (m, 2H, C ⁵ H ₂ ), 0.87 (t, 3H, C ¹¹ H ₃ , J = 6.8 Hz), 0.92-1.03 (m, 2H, C ² H _b , C ⁴ H _a ), 1.19-1.31 (m, 10H, C ⁶ H ₂ , C ⁷ H ₂ , C ⁸ H ₂ , C ⁹ H ₂ , C ¹⁰ H ₂ ), 1.57 (m, 1H, C ³ H), 1.76 (m, 1H, C ⁴ H _b ), 7.55 (broad s, 2H, Py, W _1/2 = 18.8 Hz), 7.95 (br.s, 1H, Py, W _1/2 = 20.7 Hz), 8.6 (m, 2H, Py). ¹³ C NMR spectrum (δ, ppm, THF-d ₈ ): 14.60 (C ¹¹ ), 21.40 (C ⁵ ), 23.60 (C ¹⁰ ), 29.91 (C ⁸ ), 30.74 (C ⁷ ), 31.96 ( C ² ), 33.05 (C ⁹ ), 36.55 (C ⁴ ), 40.21 (C ⁶ ), 43.78 (C ³ ), 124.21 (Py), 137.85 (Pyr), 145.34 (Pyr). ¹¹ B NMR spectrum (δ, ppm, THF-d ₈ ): = 3.11.

1-Fluoro-3-butylborolane Py (1a): b.p. 101 ° C (15 mmHg). ¹ H NMR spectrum (δ, ppm, CD ₂ Cl ₂ ): 0.39 (m, 1H, C ² H _a ), 0.72-0.81 (m, 2H, C ⁵ H ₂ ), 0.92 (m, 3H, C ⁹ H ₃ ), 1.20-1.57 (m, 8H, C ² H _b , C ⁴ H _a , C ⁶ H _2, C ₇ H ₂ , C ⁸ H ₂ ), 1.85 (m, 1H, C ³ H) 2.1 (m, 1H, C ⁴ H _b ), 7.2 (br.s, 2H, Pyr, W _1/2 = 18 Hz), 7.43 (m, 1H, Pyr), 8.3 (m, 2H, Pyr). ¹³ C NMR spectrum (δ, ppm, CD ₂ Cl ₂ ): 14.22 (C ⁹ ), 22.20 (C ⁵ ), 23.35 (C ⁸ ), 31.67 (C ⁷ ), 32.70 (C ² ), 36.06 ( C ⁴ ), 39.06 (C ⁶ ), 43.04 (C ³ ), 124.00 (Py), 135.29 (Py), 149.51 (Py). ¹¹ B NMR Spectrum (δ, ppm, CD ₂ Cl ₂ ): 6.2.

1-Chloro-3-hexylborolane Py (1c): T. boil. 107 ° C (10 mmHg). ¹ H NMR spectrum (δ, ppm, THF-d ₈ ): 0.12 (t, 1H, C ² H _a , J = 13.1 Hz), 0.42-0.51 (m, 2H, C ⁵ H ₂ ), 0.89 (t, 3H, C ¹¹ H ₃ , J = 7.2 Hz), 0.96-1.06 (m, 2H, C ² H _b , C ⁴ H _a ), 1.19-1.40 (m, 10H, C ⁶ H ₂ , C ⁷ H ₂ , C ⁸ H ₂ , C ⁹ H ₂ , C ¹⁰ H ₂ ), 1.60 (m, 1H, C ³ H), 1.81 (m, 1H, C ⁴ H _b , 7.31 (br.s, 2H , Py, W _1/2 = 18.0 Hz), 7.72 (br.s, 1H, Py, W _1/2 = 19.8 Hz), 8.2 (br.s, 2H, Py). ¹³ C NMR spectrum (δ, m dd, THF-d ₈ ): 14.64 (C ¹¹ ), 22.16 (C ⁵ ), 23.68 (C ¹⁰ ), 30.01 (C ⁸ ), 30.96 (C ⁷ ), 31.89 (C ² ), 33.13 (C ⁹ ), 36.64 (C ⁴ ), 40.32 (C ⁶ ), 43.88 (C ³ ), 125.10 (Py), 137.20 (Py), 150.50 (Py). ¹¹ B NMR spectrum (δ, ppm, THF-d ₈ ): 2.84.

1-Chloro-3-benzylborolane · Py (1 g): b.p. 134 ° C (10 mmHg). ¹ H NMR spectrum (δ, ppm, CDCl ₃ ): 0.24 (t, 1H, C ² H _a J = 10.8 Hz), 0.40-0.47 (m, 2H, C ⁵ H ₂ ), 0.92 (m, 1H, C ² H _b ), 1.1 (m, 1H, C ⁴ H _a ), 1.71-1.79 (m, 1H, C ⁴ H _b ), 1.91 (m, 1H, C ³ H), 2.61 (m, 2H , C ⁶ H ₂ ), 7.15-7.28 (m, 5H, CH _arom ), 7.44 (m, 2H, Py), 7.5 (m, 1H, Py), 8.6 (m, 2H, Py). ¹³ C NMR spectrum (δ, ppm, CDCl ₃ ): 22.0 (C ⁵ ), 30.80 (C ² ), 35.49 (C ⁴ ), 44.83 (C ³ ), 45.40 (C ⁶ ), 124.42 (Py) 124.90 (C ¹⁰ ), 127.80 (C ^{9.9 '} ), 129.01 (C ^8.8' ), 137.63 (Py), 141.21 (Py), 144.13 (C ⁷ ). ¹¹ B NMR Spectrum (δ, ppm, CDCl ₃ ): 5.20.

Claims (1)

The method of obtaining pyridinates 1-fluoro (chloro) -3-alkyl (aryl) borolanes of the general formula (1)

where R = Bu, X = F (a); R = Hex, X = F (b);
R = Hex, X = Cl (c); R = Bn, X = Cl (g),
characterized in that unsaturated compounds selected from the series hex-1-ene, oct-1-ene or allylbenzene react with AlEt ₃ triethylaluminum in the presence of a Cp ₂ ZrCl ₂ catalyst in a ratio of 10: 12: 0.5 in hexane in an inert gas atmosphere with stirring for 7 hours, then boron trifluoride etherate BF ₃ · Et ₂ O or boron chloride BCl ₃ and pyridine are added to the reaction mixture cooled to -10 ° C and pyridine in an amount twice with respect to AlEt ₃ , followed by stirring at room temperature for 30-60 minutes