Improved Buchner reaction selectivity in the copper-catalyzed reactions of ethyl 3-arylmethylamino-2-diazo-3-oxopropanoates
作者:Jing Liu、Jianzhuo Tu、Zhanhui Yang、Chol-Ung Pak、Jiaxi Xu
DOI:10.1016/j.tet.2017.06.029
日期:2017.8
Buchner reaction and aliphatic 1,4-C-H insertion under the catalysis of copper salts. The less steric N-alkyl substituents in the amide moiety generally favor the aliphatic 1,4-C-H insertion, while the more steric N-alkyl substituents generally favor the Buchner reaction. Compared with rhodium and ruthenium-catalyzed conditions, the current copper-catalyzed conditions improved the Buchner reaction selectivity
3-烷基(芳基甲基)氨基-2-重氮-3-氧代丙酸乙酯(重氮酰胺基乙酸酯)通常同时生成环庚[ c ]吡咯烷酮(Buchner产物)和β-内酰胺(1,4-插入产物),并显示出明显的N-铜盐催化下分子内布氏反应与脂肪族1,4-CH插入之间的取代基控制的化学选择性。酰胺部分中较少的空间N-烷基取代基通常有利于脂肪族1,4-CH插入,而较高的空间N-烷基取代基通常有利于布氏反应。与铑和钌催化的条件相比,当前的铜催化条件提高了3-烷基(芳基甲基)氨基-2-重氮-3-氧代丙酸乙酯的布氏反应选择性。