Solvent-Controlled Divergent 1,2-Dialkylation and 1,1,2-Bromodialkylation of Terminal Alkynes to Access Difluoroalkylated Cyclopentanes

Abstract

The 1,1,2-trifunctionalization of alkynes is an atom-economical strategy that enables the rapid construction of multiple C–C and C–heteroatom bonds in a single synthetic operation. Herein, we present a radical addition-translocation-cyclization cascade that achieves the 1,1,2-trifunctionalization of terminal alkynes, delivering difluoromethyl-containing polysubstituted cyclopentanes with high efficiency. Notably, simple solvent modulation enables a switchable divergence to 1,2-difunctionalized products, offering enhanced synthetic flexibility. The protocol features mild conditions, operational simplicity, and broad substrate tolerance, and is well-suited for both scale-up synthesis and late-stage diversification.