Photoredox-driven tandem ring-opening and vinylation: a route to distal alkenyl ketones from cyclopropenes

Abstract

An organocatalytic strategy enabling sequential C–C bond fragmentation and reconstruction via hydroalkylation of cyclopropenes has been successfully achieved under ambient conditions. This method utilized a proton-coupled electron transfer (PCET) mechanism to activate structurally constrained tertiary cycloalkanols across a range of ring sizes. The generated cyclopropyl radicals undergo regioselective addition to cyclopropenes, followed by efficient cleavage of the transient cyclopropyl radical intermediate, yielding distally unsaturated ketones with excellent diastereoselectivity. Notably, this transformation demonstrates a broad substrate scope, accommodating diverse functional groups while maintaining a high atom economy, offering an effective strategy for synthesizing polysubstituted alkenyl ketone analogs.