Expedient (3+3)-annulation of carbonyl ylides with azaoxyallyl cations: formal access to oxa-benzo[c]azepin-3-ones

Abstract

The cascade carbon–carbon and carbon–nitrogen bond formation between in situ generated carbonyl ylides and azaoxyallyl cations, facilitated by Rh-catalysis and a base, has been achieved to furnish oxa-benzo[c]azepin-3-ones. Substrate scope, functional group diversity, scale-up and post-synthetic utilities are the important practical features.