Zinc-Mediated Carbene Insertion to C–Cl Bonds of Chloromethanes and Isolable Zinc(II) Isocyanide Adducts

The zinc adduct {[HB(3,5-(CF3)2Pz)3]Zn}(+), which was generated from [HB(3,5-(CF3)2Pz)3]ZnEt and [Ph3C]{B[3,5-(CF3)2C6H3]4}, catalyzes the activation of C-halogen bonds of chloromethanes via carbene insertion. Ethyl diazoacetate serves as the carbene precursor. The presence of {[HB(3,5-(CF3)2Pz)3]Zn}(+) in the reaction mixture was confirmed by obtaining {[HB(3,5-(CF3)2Pz)3]Zn(CN(t)Bu)3}(+) using CN(t)Bu as a trapping agent. {[HB(3,5-(CF3)2Pz)3]Zn(CN(t)Bu)3}(+) loses one zinc-bound CN(t)Bu easily to produce five-coordinate {[HB(3,5-(CF3)2Pz)3]Zn(CN(t)Bu)2}(+).