The âone-potâ stereoselective conversion of N-(4-nitrobenzene)sulfonyl-α-amino acid tert-butyl esters into the corresponding N-alkyl-α-(4-nitrophenyl)-α-amino esters has been realized through N-alkylation of the starting amido esters, followed by NâCα migration of the p-nitrophenyl group and the loss of sulfur dioxide; the asymmetric induction is determined by an intermediate non-racemic enolate, without the need of an external source of chirality.
通过对起始
氨基酯进行 N-烷基化,然后对
硝基苯基发生 NâCδ迁移并失去
二氧化硫,实现了 N-(4-
硝基苯基)磺酰基-δ-
氨基酸叔丁酯到相应的 N-烷基-δ-(4-
硝基苯基)-δ-
氨基酸酯的 "一锅 "立体选择性转化;不对称诱导是由中间的非气相烯醇决定的,不需要外部的手性源。