Cyclization of Vinyl Diazo Compounds with Benzofuran-Derived Azadienes Enabled by NaBArF4

Org Lett. 2023 Apr 7;25(13):2243-2247. doi: 10.1021/acs.orglett.3c00493. Epub 2023 Mar 27.

Abstract

An unprecedented cycloaddition of vinyl diazo compounds with benzofuran-derived azadienes catalyzed by rarely independently used NaBArF4 has been established. Benzofuran-fused hydropyridines were constructed with excellent yields and high diastereoselectivity via a Na+-catalyzed inverse-electron-demand aza-Diels-Alder reaction. Notably, this transformation also features good compatibility with a one-pot protocol to deliver the spiro[benzofuran-cyclopentene] skeleton, as well as perfect atom economy and simple reaction conditions.