Transition-metal-free synthesis of indole-fused dibenzo[b,f][1,4]oxazepines via Smiles rearrangement

Abstract

A one-pot transition-metal-free approach for the synthesis of indole-fused dibenzo[b,f][1,4]oxazepines from 2-(1H-indol-2-yl)phenol and 1,2-dihalobenzenes or 2 halonitroarenes has been developed. The proposed mechanism for this transformation features a Smiles rearrangement favoured over a direct intramolecular nucleophilic cyclization, which affords the corresponding products in different regioselectivities. This reaction also features simple reaction conditions and wide functional group tolerance.