An efficient sequential one-pot base mediated C-O and Pd-mediated C-C bond formation: synthesis of functionalized cinnamates and isochromenes

An efficient sequential one-pot intermolecular oxy-Michael addition and intermolecular Heck coupling for the synthesis of functionalized cinnamates is presented. Bulky tert-butyl acrylate was identified as a more suitable Michael acceptor for initial oxy-Michael addition, as it precludes the formation of undesired cross condensed ester. Most importantly, the present method was further divergently extended to the successful synthesis of isochromenes via a sequential one-pot O-allylation and subsequent intramolecular Heck cyclization.