Control of 6‐<i>Exo</i> and 7‐<i>Endo</i>Cyclizations of Alkynylamides using Platinum and Bismuth Catalysts

Abstract

The rules of cyclization: Alkynylamides are regioselectively cycloisomerized into piperazin-2-one and 1,4-diazepan-2-one derivatives by using catalytic amounts of appropriate metal catalysts. A 6-exo-dig addition proceeds in the presence of Bi(OTf)3, while the 7-endo-dig addition occurs with PtCl2 for the same substrate. (see scheme; Ns=o-nitrobenzenesulfonyl, Ts=p-toluenesulfonyl, Cbz=benzyloxycarbonyl, DCE=dichloroethane) Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.