Asymmetric Addition of Trimethylsilyl Cyanide to Aldehydes Catalyzed by Al(Salen) and Mn(Salen) Complex

초록

Chiral cyanohydrins are useful synthetic intermediates. The two functional groups can be easily converted into various homochiral products such as α-hydroxy acids1,2, α-hydroxy aldehydes3, α-hydroxy ketones3, β-hydroxy amines2,3, and α-amino acid derivatives4. Nume rous asymmetric caytalysts5 are now available for the conversion of the aldehydes and ketones into the non-racemic cyanohydrins. Al(Salen) plus trimethylphosphine oxide6 is used as the catalyst for the reaction of aldehydes and trimethylsilyl cyanide(TMSCN). The resulting cyanohydrin shows over 92% yield and 80% ee. When Mn(Salen)7 is employed, the yield retains similarly over 92% but ee is dropped to over 52%.