Design of a new bifunctional asymmetric catalyst from carbohydrates: application to catalytic asymmetric cyanosilylation of aldehydes and acetophenone
作者:Motomu Kanai、Yoshitaka Hamashima、Masakatsu Shibasaki
DOI:10.1016/s0040-4039(00)00174-x
日期:2000.4
A new active Lewis acid–Lewis base bifunctional asymmetric catalyst 7 was developed using carbohydrate as a scaffold and this catalyst was applied to the asymmetric cyanosilylation of aldehydes and acetophenone. The β-Ph group at the 6-position of 7 was found to be important for a high asymmetric induction (up to 80% ee) by bringing the Al and the phosphine oxide at optimum positions for a dual activation
以碳水化合物为骨架,开发了一种新的活性路易斯酸-路易斯碱双功能不对称催化剂7,该催化剂用于醛类和苯乙酮的不对称氰基硅烷化反应。通过将Al和氧化膦置于羰基化合物和TMSCN的双重活化的最佳位置,发现7位6位的β-Ph基团对于高度不对称感应(至多80%ee)很重要。