作者:Bjørg Møller、Kjell Undheim
DOI:10.1016/s0040-4020(98)00267-1
日期:1998.5
Stereoselective syntheses of cyclic α-amino acids are described. The α-carbon of the amino acid is incorporated into a five- or six-membered vicinal dimethylenecycloalkane or conjugated methylenecycloalkene. Palladium-catalysis was used for cycloisomerization of intermediate enynes and intramolecular Heck type cyclizations of bromodienes. A stereoselective elimination from a homoallylic Pd-intermediate
描述了环状α-氨基酸的立体选择性合成。氨基酸的α-碳被掺入五元或六元邻位的二亚甲基环烷烃或共轭的亚甲基环烯烃中。钯催化用于中间体烯的环异构化和溴代双烯的分子内Heck型环化。描述了从均相Pd中间体中的立体选择性消除。通过将手性助剂(R)-2,5-二氢-3,6-二甲氧基-2-异丙基吡嗪与溴代烯烃和-炔烃逐步烷基化,可获得用于环化反应的对映体纯的底物。