Synthesis of iodo-indoloazepinones in an iodine-mediated three-component domino reaction via a regioselective 7-endo-dig iodo-cyclization pathway ±

Abstract

An efficient and rapid synthetic strategy for the naturally occurring indoloazepinone scaffold via a three-component reaction of indole-2- carboxamides, 1,3-disubstituted propargyl alcohols, and I 2 is described. The strategy involves a C-H functionalization-alkyne activation-intramolecular hydroamidation-deprotonation domino sequence. The salient feature of this sequence is regioselective electrophilic 7-endo-dig iodo-cyclization during the intramolecular hydroamidation to afford a seven-membered azepinone ring annulated to the indole. © 2011 American Chemical Society.