An oxidative coupling for the synthesis of arylated quaternary stereocentres and its application in the total synthesis of powelline and buphanidrine
作者:Katherine M. Bogle、David J. Hirst、Darren J. Dixon
DOI:10.1016/j.tet.2010.04.132
日期:2010.8
Catechol derivatives directly bonded to all-carbon quaternary stereocentres are prevalent in nature. An oxidative coupling strategy for the synthesis of this motif is described. Pivoting on the base-catalysed Michael addition of carbon-centred pro-nucleophiles to in situ generated ortho-benzoquinones, the method is broad in scope, high yielding and provides remarkably simple access to this challenging motif. The application of this methodology in the total synthesis of the crinane-type amaryllidaceae alkaloids (+/-)-powelline and (+/-)-buphanidrine is demonstrated and our efforts towards an enantioselective synthesis described. (C) 2010 Elsevier Ltd. All rights reserved.