Enantioselective cyanoformylation of aldehydes using a recyclable dimeric cinchonidine ammonium salt as an organocatalyst
作者:Rafael Chinchilla、Carmen Nájera、Francisco J. Ortega
DOI:10.1016/j.tetasy.2008.01.011
日期:2008.2
ammonium salt is used as a chiral organocatalyst in the enantioselective addition of alkyl cyanoformates to aldehydes in the presence of substoichiometric amounts of triethylamine. Quantitative yields and enantioselectivities up to 88% ee for the corresponding (R)-O-methoxycarbonyl cyanohydrins are obtained using only 1 mol % organocatalyst loading and working at 10 °C. The organocatalyst can be almost
在亚化学计量的三乙胺的存在下,将烷基氰基甲酸酯对映体对映选择性地加成,将二聚蒽基二甲基衍生的辛可尼定铵盐用作手性有机催化剂。相应的(R)-O-甲氧基羰基氰醇的定量收率和对映选择性高达88%ee,仅使用1 mol%的有机催化剂负载量并在10°C的条件下即可获得。有机催化剂可通过沉淀几乎定量地回收并再利用。