Base-Mediated Annulation of ortho-Iminophenols and ortho-Vinylphenols with MBH Carbonates of Isatins: Straightforward Access to Dihydrobenzofuran and Benzofuran Derivatives

J Org Chem. 2024 Nov 1;89(21):15472-15489. doi: 10.1021/acs.joc.4c01501. Epub 2024 Oct 15.

Abstract

We have developed a convenient synthetic protocol for efficient construction of significant dihydrobenzofuran and benzofuran scaffolds by Lewis base-mediated annulation reaction ortho-iminophenols and ortho-vinylphenols with MBH carbonates of isatins under mild and metal-free conditions. The selective generation of different kinds of dihydrobenzofuran and benzofuran derivatives was successfully achieved by employing different substituted isatin-derived MBH carbonates with ortho-N-tosyliminophenols and ortho-vinylphenols. The features included broad substrate scopes, excellent functional group compatibility, high molecular diversity, and atomic economy.