Trifluoromethylative homo-coupling of carbonyl compounds

Carbonyl compounds are abundant in nature and represent a substantial portion of biomass resources. Despite significant recent progress in homo-coupling of carbonyl compounds, achieving their deoxy-functionalization homo-coupling remains a highly intricate challenge. Herein, we report an entirely novel reaction paradigm: the trifluoromethylative homo-coupling of carbonyl compounds via hydrazones, which enables the formation of three C(sp3)–C(sp3) bonds in a single step. This method provides a new pathway for synthesizing trifluoromethylative coupling product which has unique applications in both fields of medical and material sciences. Mechanistic investigations have unveiled that the formation of a trifluoromethyl-substituted benzyl radical plays a pivotal role as a key intermediate in this reaction. In this paper, for the first time, we present a new reaction mode: the trifluoromethylative homo-coupling of carbonyl compounds via hydrazones. Significantly, this protocol not only introduces the CF3 group commonly into natural and abundant aldehydes but also accomplishes the deoxygenative homo-coupling of aromatic aldehydes. This process leads to the creation of three C–C bonds in a single step, establishing a novel pathway for homo-coupling reactions of carbonyl compounds. [Display omitted]