Synthesis of cyanooxovanadate and cyanosilylation of ketones

The cyanosilylation was performed by using metavanadate catalysts, and in situ measurements revealed the formation of [VO 2 (CN) 3 ] 2− and [VO 4 TMS 2 ] − under reaction conditions. The reaction of [VO 2 (CN) 3 ] 2− , trimethylsilyl cyanide (TMSCN), and water afforded [VO 4 TMS 2 ] − and CN − , which reacted with ketones to yield the corresponding cyanohydrin trimethylsilyl ethers over [VO 2 (CN) 3 ] 2− . Compound [VO 2 (CN) 3 ] 2− showed high catalytic performance for cyanosilylation of various carbonyl compounds. In the case of n -hexanal, turnover frequency reached up to 250 s −1 . Two key catalytic vanadium species involved in cyanosilylation of ketones were observed by in situ measurement.