NMM-promoted decarboxylative C(sp3)–C(sp3) coupling of coumarin-3-carboxylic acids and indolin-3-ones

Abstract

In this study, a tandem reaction of coumarin-3-carboxylic acids with indolin-3-ones, involving Michael addition and decarboxylation, enables the construction of C(sp³)–C(sp³) bonds at room temperature. This cascade strategy provides straightforward access to biologically important indolin-3-one-substituted chroman-2-ones in good to excellent yields with excellent diastereoselectivity. The advantages of this approach include the avoidance of metal catalysts and high-temperature conditions, a broad substrate scope, and high functional group compatibility.