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 .