New vistas in synthesis of optically active polymers

Abstract

A rational approach has been developed for unequivocally establishing asymmetric induction in the back bone of vinyl polymers based on 1,2-disubstituted and 1-substituted olefins. Towards this end, the principle of protecting group chemistry has been utilized to connect chiral auxiliaries to functional monomers in the form of boronate esters and azomethine linkages. This approach enables to remove the auxiliaries quantitatively after polymerization. For 1,2-disubstituted olefin based systems, the role of the type of chiral auxiliary used, nature of comonomers and the location of the chiral auxiliaries with respect to the polymerizable group on enantioselectivity has been elucidated. A divinyl functional monomer bearing chiral auxiliary in the form of azomethine protecting group has been synthesized from readily accessible precursors. This monomer was found to undergo asymmetric cyclopolymerization-tion. An overview of the results obtained from these investigations is presented.