对于芳基苄位的羟基，可以用 TMSCN 直接转化为腈，反应的好坏与邻位的碳上是否有烷基的氢质子有关。
TMSCN 双芳基甲醇氰化反应示例一
Thionyl chloride (50 ml) was added to bis(4-fluorophenyl)methanol (24.2 g) at 0 deg C and after stirring for 30 min, the mixture was poured into 2N hydrochloric acid (500 ml). The mixture was extracted with ethyl acetate and the organic layer was dried over calcium chloride and concentrated under reduced pressure. The resulting residue was dissolved in dichloromethane (200 ml) and after addition of trimethylsilylcyanide (16.4 ml), titanium tetrachloride (13.4 ml) was added dropwise at 0 degC. The mixture was stirred for 50 min. Methanol (5 ml) was added to the reaction mixture and the mixture was poured into saturated aqueous sodium hydrogen carbonate. The mixture was extracted with ethyl acetate and washed with saturated brine. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give the title compound (21.8 g) oil.
TMSCN 单芳基苄醇氰化反应示例二
To solution of 4-(1-cyclohexyl-3-ethyl-1H-indazol-6-yl)-4-hydroxy-cyclohexane carboxylic acid ethyl ester (13.5 g, 33.9 mmol) in CH2Cl2 (135 mL) cooled to 0 °C was added trimethylsilyl cyanide (22.6 mL, 169 mmol) followed by a slow addition of SnCl 4 (13.6mL of a 1.0 M solution in CH 2 Cl 2 , 13.6 mmol). The reaction mixture was allowed to warm to room temperature overnight. K 2 CO 3 (18.7 g, 136 mmol) and KFâ2H2O (12.8 g, 136mmol) were added, followed by dropwise addition of H2O (4.30 mL, 239 mmol). The reaction mixture was stirred vigorously for 90 min, after which silica gel (25 g) was added. The mixture was filtered and washed thoroughly with CH2Cl2. The filtrate was washed with saturated aqueous NaHCO3 (250 mL), dried over MgSO 4 , filtered, and concentrated to yield 13.2 g oily product of (96% recovery) cyano-4-(1-cyclohexyl-3-ethyl-1H-indazol-6-yl)cyclohexanecarboxylic acid ethyl ester as a mixture of diastereoisomers. For characterization purposes, a sample of each diastereoisomer was obtained by chromatographic purification on silica gel eluting with 4:1 hexanes/EtOAc.
