Zinc chloride, reaction with phenylmagnesium bromide

Prsparation. The first preparation of VF dates back to 1901 and the reaction of zinc with l,l-difluoro-2-bromoethane [359-07-9] (3). Phenylmagnesium bromide in ether and potassiiun iodide solution can replace the metal for de-halogenation (4,5). Most approaches to VF s3uithesis have employed reactions of acetylene [74-86-2] with hydrogen fluoride (HF) either directly (5-8) or utilizing a catalyst (6,9-13) based on merciuy or aluminum (6,9,12,14). In another process, an acetylene/HF mixture is passed over a mercuric chloride or fluoride catalyst, which also produces vinyUdene fluoride and difluoroethane as by-products (10). Another S3uithesis (11) consists of two steps in which 1,1-difluoroethane (DFE) is... 

Zinc(II) chloride-tetramethylethylenediamine complex (4.23 g, 16.7 mmol), 1,10-phenanthroline (101 mg, 0.56 mmol), and benzo[/t]quinoline (1.00 g, 5.6 mmol) are placed in a Schlenk tube. To this mixture a solution of phenylmagnesium bromide (33.5 mL, 1.00 M, 33.5 mmol) in tetrahydrofuran is added dropwise at 0 °C. After stirring for I h, a 0.1-M solution of tris(acetylacetonato)iron in tetrahydrofuran (5.6 mL, 0.56 mmol) and 1,2-dichloro-2-methylpropane (1.42 g, 11.2 mmol) are sequentially added. The reaction mixture is stirred at 0 °C for 16 h and is quenched by the addition of a saturated aqueous solution of sodium bicarbonate (40 mL). After extraction with ethyl acetate (25 mL, 3 times), the organic layer is dried over sodium sulfate and concentrated under reduced pressure. The crude product is purified by silica gel chromatography (eluent first hexane to elute the biphenyl, then toluene) to afford 10-phenylbenzo[A]quinoline as a colorless solid mp 90.6-92.5 1.39 g (98%). ... 

In a dry reaction vessel, a mixture of l,2-bis[di(4-fluorophenyl)phosphano]benzene (51.8 mg, 0.10 mmol), zinc(II) chloride (a 1.0-M tetrahydrofuran solution, 7.5 mL, 7.5 mmol), and phenylmagnesium bromide (1.17-M tetrahydrofuran solution, 12.8 mL, 15.0 mmol) in toluene (20 mL) is stirred at room temperature for 0.5 h. The resulting suspension is cooled to 0 °C before iron(III) chloride (0.10-M tetrahydrofuran solution, 0.50 mL, 0.050 mmol) and 7-oxabenzonorbomadiene (0.72 g, 5.0 mmol) are added and the reaction is stirred at 0 °C for 2 h. The reaction mixture is quenched with an ice-cooled, degassed solution of 5% acetic acid/methanol and then extracted with n-hexane and 30% diethyl ether/ -hexane, passed through a pad of Florisil, and concentrated in vacuo. The product is obtained as a colorless solid after column chromatography on silica gel (n-hexane/EtOAc, 20 1 Rf = 0.36) 1.02 g (92%). ... 

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