Dibenzyl and diallyl 2,6-bisiminopyridinezinc (ii) complexes: Selective alkyl migration to the pyridine ring leads to remarkably stable dihydropyridinates

Abstract

Diorganozinc compounds (ZnR2) with R = CH2Ph or CH2CH[double bond, length as m-dash]CH2 react with 2,6-bisiminopyridines (iPrBIP) to afford thermally stable dihydropyridinate(−1) complexes, and do not react if R = CH2SiMe3 or CH2CMe2Ph. NMR studies reveal that dibenzylzinc binds iPrBIP at −80 °C, yielding the unstable complex [Zn(CH2Ph)2(iPrBIP)]. Above −20 °C, this undergoes selective alkyl migration to the remote 4 position of the central pyridine ring.