Synthesis of 2-aminobenzofurans via base-mediated [3 + 2] annulation of N-phenoxy amides with gem-difluoroalkenes

Abstract

Efficient, mild and metal-free [3 + 2] annulation of N-phenoxy amides with gem-difluoroalkenes has been realized via a base-mediated tandem [3,3]-sigmatropic rearrangement, which gives direct access to 2-aminobenzofuran derivatives involved in the one-pot cleavage of multiple bonds including C–H, O–N and twofold C–F bonds. The subsequent success of the on-DNA compatible synthesis and the application of the obtained products as potential anticancer agents further demonstrates the versatility of this transformation.