One-pot preparation of pyrrole derivatives via the copper-catalyzed [4+1] annulation of propargylic amines with ethyl glyoxylate and phenylglyoxal in the presence of piperidine
作者:Norio Sakai、Hiroki Suzuki、Hiroaki Hori、Yohei Ogiwara
DOI:10.1016/j.tetlet.2016.11.097
日期:2017.1
We describe how copper(II) chloride efficiently catalyzes the [4+1] annulation of propargylamines with either ethyl glyoxylate or phenylglyoxal functioning as a C1 unit, in the presence of piperidine, which leads to a straightforward and one-pot preparation of pyrrole derivatives. The key feature in this annulation is the in-situ generation of an N,O-hemiacetal intermediate from either the glyoxylate
我们描述了氯化铜(II)在哌啶的存在下如何有效地催化乙醛酸乙酯或苯基乙二醛作为C1单元的炔丙基胺的[4 + 1]环化反应,从而导致吡咯衍生物的简单直接制备。这种环化的关键特征是由乙醛酸酯或乙二醛与仲胺原位生成N,O-半缩醛中间体。