Rhodium/Amine Dual Catalytic System for Reassembling C≡C Bonds of Conjugated Alkynes with Cyclopropenes via Cutting/Insertion Cascade

Abstract

Amines are powerful organocatalysts that are well-documented in catalyzing carbonyl compounds to realize transformations. However, they are rarely applied in alkyne activations. Herein, we disclose an efficient amine/Rh(II) dual catalytic system to reassemble the C≡C bond of conjugated alkynes with cyclopropenes, which enables construction of α-vinyldicarbonyl derivatives under very mild reaction conditions. Vinyl cyclopropylamines might be involved as key intermediates through ring-opening of cyclopropenes, catalytic amination of alkynes, and tandem cyclopropantion sequences in high atom and step-economies. This formal cutting/insertion cascade platform is compatible with a broad substrate scope including complex natural and unnatural molecules for late-stage functionalization.