Catalytic enantioselective C–H functionalization of indoles with α-diazopropionates using chiral dirhodium(II) carboxylates: asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A
作者:Takayuki Goto、Yoshihiro Natori、Koji Takeda、Hisanori Nambu、Shunichi Hashimoto
DOI:10.1016/j.tetasy.2011.05.011
日期:2011.4
first catalytic asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A, a potent plant-growth inhibitor. Furthermore, the Fujioka protocol using a combination of TMSOTf and 2,2′-bipyridyl was shown to be superior for the removal of the N-MOM group.
N-甲氧基甲基(MOM)保护的2,3-未取代的吲哚与α-重氮丙酸酯的对映选择性C–H功能化是通过四[二] [ N-邻苯二甲酰基-(S)-三乙基丙氨酸]铑(Rh 2)催化实现的。((S)-PTTEA)4,以高收率提供对映体选择性高达86%ee的α-甲基-3-吲哚基乙酸酯。该协议的有效性通过强力植物生长素Acremoauxin A的(+)-α-甲基-3-吲哚基乳酸片段的首次催化不对称合成得到证明。此外,结合使用TMSOTf和2,2'-联吡啶的Fujioka协议被证明对于去除N更为有效。-妈妈组。