Activated Zinc Complexes Supported by a Neutral, Phosphinimine-Containing Ligand: Synthesis and Efficacy for the Polymerization of Lactide

A general approach for the synthesis of cationic zinc complexes supported by neutral ancillary ligands has been developed and exploited to prepare [LH][B(C6F5)(4)] (L = 4-(2,6-Pr-i(2)-C6H3NPPh2)dbf), 1a, and [LH][SO3CF3], 1b) using [HNMe2Ph][B(C6F5)(4)] and triflic acid, respectively. Reactions of la and 1b with diethylzinc afforded the corresponding complexes [LZnEt][B(C6F5)(4)], 2a, and [LZnEt(OSO2CF3)], 2b. Both zinc complexes have exhibited notable activities for the catalytic polymerization of L-lactide.