Selective Synthesis of α,α-Difluoro- and α-Monofluoro Methylene Substituted Arenes by Defluoro C–C Bond Coupling

A mild and site-selective method for synthesizing α,α-difluoro- and α-monofluoro benzylic compounds by defluoro/C–C coupling reactions is presented. The process utilizes readily available aryl–CF3 and −CF2R substrates as building blocks, along with organodiboron reagents and a Lewis base activator. This methodology efficiently produces benzylic fluoroarenes with adjacent quaternary or tertiary carbons in high yields and with excellent site selectivity. The resulting products feature an alkenyl boronic ester, providing a versatile handle for subsequent synthetic modifications.