Carbon dioxide: a reagent for the simultaneous protection of nucleophilic centres and the activation of alternative locations to electrophilic attack.
作者:Alan R. Katritzky、Wei-Qiang Fan、Kunihiko Akutagawa
DOI:10.1016/s0040-4020(01)87558-x
日期:1986.1
N-Methyl- and M-ethyl-aniline are regiospecifically converted into a range of ortho-substituted derivatives, using carbon dioxide both for M-protection and as an intermediate carbanion stabilizing group, and -butyllithium to lithiate the ortho-carbon atom. The resulting lithium N-(ortho-substituted-phenyl)-N-methyl- and -N-ethyl-carbamates undergo smooth acid-catalysed decarboxylation under mild conditions
N-甲基-和M-乙基苯胺被区域特异性地转化为一系列邻位取代的衍生物,同时使用二氧化碳进行M保护和作为中间的碳负离子稳定基团,同时使用丁基丁基锂对邻碳原子进行锂化。所得的N-(邻取代苯基)-N-甲基氨基甲酸锂和-N-乙基氨基甲酸锂在温和的条件下经历平滑的酸催化脱羧作用。没有检测到α-取代的产物。