A Direct and General Method for the Reductive Alkylation of Tertiary Lactams/Amides: Application to the Step Economical Synthesis of Alkaloid (−)-Morusimic Acid D
作者:Kai-Jiong Xiao、Yu Wang、Ying-Hong Huang、Xiao-Gang Wang、Pei-Qiang Huang
DOI:10.1021/jo4007656
日期:2013.9.6
Full details of the direct and general method for the reductive alkylation of tertiary lactams and amides to give tertiary sec-alkylamines are presented. This one-pot method consists of in situ activation of a lactam or an amide with Tf2O/DTBMP, addition of a Grignard reagent, and reduction of the resulting iminium intermediates. Alkyl, benzyl, and aryl Grignard reagents and several reductants or reducing
给出了直接和通用的方法将叔内酰胺和酰胺还原烷基化以得到叔仲烷基胺的全部细节。这种一锅法包括用Tf 2 O / DTBMP原位活化内酰胺或酰胺,添加格氏试剂和还原生成的亚胺中间体。烷基,苄基和芳基格氏试剂和几种还原剂或还原条件(LiAlH 4,NaBH 4,汉茨酯,Bu 3 SnH,Pd(OH)2 / C,H 2)可以有效地使用。取代的内酰胺的还原烷基化表现出良好至优异的1,3-不对称诱导,可在6:1(LiAlH 4),11:1(Et 3 SiH)和20:1(催化)中提供相应的二或三取代的吡咯烷/哌啶氢化)分别为顺/反非对映选择性。该方法的多功能性通过其在哌啶生物碱(-)-桑木酸的简明立体选择性合成中的应用得到证明。