Microwave-assisted one-pot synthesis of dibenzo[b,d]oxepines via domino C–C coupling and a cyclo-condensation pathway

Abstract

A microwave-assisted [Pd]-catalyzed domino one-pot approach to dibenzo[b,d]oxepines starting from 2-bromo-/2-iodo-aryl ethers and 2-formylphenylboronic acids/pinacol boronic acid esters has been developed. The present strategy enables quick access to various substituted dibenzo[b,d]oxepine products in good to high yields and with adequate functional group tolerance. The reaction mechanism involves a tandem intermolecular arylation of 2-bromo-/iodo-aryl ethers and subsequent intramolecular cyclo-condensation to produce fused cyclic ethers. In addition, late-stage functionalization was conducted.