Diastereoselective Imine-Bond Formation through Complementary Double-Helix Formation
作者:Hidekazu Yamada、Yoshio Furusho、Eiji Yashima
DOI:10.1021/ja301430h
日期:2012.5.2
different stereostructures are synthesized and used as templates for diastereoselective imine-bond formations between two achiral carboxylic acid monomers bearing a terminal aldehyde group and racemic 1,2-cyclohexanediamine, resulting in a preferred-handed double helix stabilized by complementary salt bridges. The diastereoselectivity of the racemic amine is significantly affected by the chirality of
chloroform in the presence of the corresponding optically inactive carboxylic acid dimer or optically active amidine dimer linked by a trans-azobenzene unit as the template, respectively. The cis-azobenzene-linked carboxylic acid template markedly slowed the monomer conversions, and hence a reversiblephotocontrolled dimerization was achieved by light-induced cis–trans isomerization upon alternative