Reactions of Zinc Dialkyls with (Perfluorophenyl)boron Compounds:  Alkylzinc Cation Formation vs C₆F₅ Transfer

Reaction between ZnR 2 and [H(OEt 2 ) 2 ][B(C 6 F 5 ) 4 ] in ether leads to the salts [RZn(OEt 2 ) 3 ][B(C 6 F 5 ) 4 ], while mixtures of ZnR 2 (R = Me, Et) and B(C 6 F 5 ) 3 in toluene- d 8 undergo facile alkyl/C 6 F 5 group exchange to give Zn(C 6 F 5 ) 2 ·(toluene). Mixtures of ZnR 2 and B(C 6 F 5 ) 3 in hydrocarbon/diethyl ether solvent mixtures react with alkyl transfer to afford the ion pairs [RZn(OEt 2 ) 3 ][RB(C 6 F 5 ) 3 ], whereas the reaction of ZnEt 2 with [Ph 3 C][B(C 6 F 5 ) 4 ] in toluene- d 8 proceeds with β-H abstraction to give ethene and Ph 3 CH, with the subsequent rapid formation of Zn(C 6 F 5 ) 2 .