Regioselective Electrophilic C–H Bond Activation in Triazolylidene Metal Complexes Containing a N‑Bound Phenyl Substituent

Transmetalation of a 1,4-diphenyl-substituted 1,2,3-triazolylidene silver complex with an electrophilic metal center, e.g., RuII, IrIII, or RhIII, induces spontaneous and chemoselective cyclometalation involving C–H bond activation of the N-bound phenyl group exclusively. Less electrophilic metals such as IrI, RhI, and PtII yield a monodentate triazolylidene complex, while cyclometalation with borderline cases (PdII) or the activation of the C-bound phenyl ring requires acetate as a promoter.

1,4-二苯基取代的1,2,3-三唑卡宾（1,2,3-triazolylidene）银配合物与带有亲电金属中心（如钌(II)（RuII）、铱(III)（IrIII）或铑(III)（RhIII））的金属发生转金属化（transmetalation）反应时，可引发自发且具有化学选择性的环金属化过程，该过程专一性地仅涉及氮配位苯基的C-H键活化。亲电性较弱的金属（如铱(I)（IrI）、铑(I)（RhI）与铂(II)（PtII））仅能生成单齿三唑卡宾配合物；而对于亲电性处于边界的金属（如钯(II)（PdII）），或是需要活化碳连接苯基环的场景，则需以乙酸根（acetate）作为促进剂。