Synthesis, Reactivity, and Catalytic Applications of Isolable (NHC)Cu(CHF₂) Complexes

Difluoromethyl copper complexes have been proposed as key intermediates in a variety of Cu-catalyzed difluoromethylation reactions. However, studies of these putative intermediates have been impeded by the low stability of these [Cu­(CHF2)] species. This report describes the synthesis of isolable N-heterocyclic carbene ligated copper­(I) difluoromethyl complexes. The stoichiometric reactions of these complexes with aryl electrophiles (i.e., diaryliodonium salts, aryl iodides, and aryl bromides) are described. In addition, N-heterocyclic carbene copper­(I) species are demonstrated to serve as catalysts for the cross-coupling of aryl iodides with (difluoromethyl)­trimethylsilane to afford difluoromethyl arene products.二氟甲基铜配合物（Difluoromethyl copper complexes）被认为是多种铜催化二氟甲基化反应的关键中间体。然而，由于这类[Cu(CHF2)]物种稳定性较低，对这些推定中间体的研究受到了阻碍。本研究报道了可分离的氮杂环卡宾(N-heterocyclic carbene)配位的铜(I)二氟甲基配合物的合成。本文还描述了该类配合物与芳基亲电试剂（即二芳基碘鎓盐、芳基碘化物及芳基溴化物）的计量反应。此外，实验证实氮杂环卡宾配位的铜(I)物种可作为催化剂，用于芳基碘化物与(二氟甲基)三甲基硅烷的交叉偶联反应，以制备二氟甲基芳烃产物。