Nucleopalladation-initiated oxyalkenylation of alkenes: a strategy to construct functionalized oxygenated heterocycles.

ABSTRACT

A convenient and efficient approach to construct functionalized oxygen heterocycles, i.e., tetrahydrofurans, tetrahydropyrans, and γ-lactones, has been reported. This process successfully provides a route to construct derivatives of naturally occurring biologically active tetrahydrofurans, especially ones with spirocyclic structure. Highly regio- and stereoselective nucleopalladation of alkynes initiates the cross-coupling between alkynamides and alkenes to give the olefin oxyalkenylation products in good to excellent yields. The hydroxyl group in the olefins cooperates with the amide in alkynamides to promote the cyclization by suppressing the ß-H elimination.