Transition‐Metal‐Free Reductive Functionalization of Tertiary Carboxamides and Lactams for α‐Branched Amine Synthesis
作者:Derek Yiren Ong、Dongyang Fan、Darren J. Dixon、Shunsuke Chiba
DOI:10.1002/anie.202004272
日期:2020.7.13
A new method for the synthesis of α‐branched amines by reductive functionalization of tertiary carboxamides and lactams is described. The process relies on the efficient and controlled reduction of tertiary amides by a sodium hydride/sodiumiodide composite, in situ treatment of the resulting anionic hemiaminal with trimethylsilyl chloride and subsequent coupling with nucleophilic reagents including
New protocols for controlled reduction of carboxamides to either alcohols or amines were established using a combination of sodium hydride (NaH) and zinc halides (ZnX2). Use of a different halide on ZnX2 dictates the selectivity, wherein the NaH‐ZnI2 system delivers alcohols and NaH‐ZnCl2 gives amines. Extensive mechanistic studies by experimental and theoretical approaches imply that polymeric zinc