Homohelicity induction of propylene-linked zinc bilinone dimers by complexation with chiral amine and α-amino esters.: Preorganization of structurally coupled homohelical subunits

Homohelicity induction of a series of propylene-linked zinc bilinone (ZnBL; linear tetrapyrrople-zinc(II) complex) dinners upon complexation with chiral amine and alpha-amino esters was investigated. Introduction of substituents such as dimethyl and diisobutyl to the central carbon of the propylene spacer gave rise to stabilization of the homohelical (PP and MM) conformers rather than the heterohelical (PM) conformer. As bulkiness of the substituent increased, stability of the homohelical conformers was raised. The preorganization of the homohelical Structures led to significantly amplified homohelicity induction upon complexation with chiral amine and alpha-amino esters. (c) 2006 Elsevier Ltd. All rights reserved.