Novel Optically Active Polyacetylenes: Synthesis and Helical Conformation of L‐Lysine‐Dendronized Poly(phenylacetylene)

Abstract

AbstractSummary: The novel chiral phenylacetylene (1) functionalized with an L‐lysine‐based dendritic peptide was synthesized and polymerized with Rh catalysts to afford the corresponding polymer [poly(1)] with moderate molecular weights in good yields. Poly(1) was soluble in common organic solvents including DMF, THF, CHCl3, AcOEt, and MeOH. The polarimetric and CD spectroscopic data indicate that poly(1) exists in a helical structure with predominantly one‐handed screw sense in THF and CHCl3. Poly(1) also assumes a helical structure in the solid state. This helical structure can be tuned by heat in CHCl3 or by the addition of a protic solvent to CHCl3 solutions.Synthesis of chiral poly(phenylacetylene) bearing a L‐lysine‐based dendritic peptide in the side chain.magnified imageSynthesis of chiral poly(phenylacetylene) bearing a L‐lysine‐based dendritic peptide in the side chain.