π-Allylnickel-Catalyzed Living Coordination Polymerization of Allene Having Homochiral Phenylcarbamoyloxy-Substituted Binaphthyl Function

Abstract

The allylnickel-catalyzed living coordination polymerization of an allene derivative possessing a homochiral substituent, (R)-2-allenyloxy-2‘-(phenylcarbamoyloxy)-1,1‘-binaphthyl (2), gave a chiral polymer which was found to have a single-handed helical conformation in solution of aprotic solvents such as chloroform and tetrahydrofuran on the basis of its circular dichroism (CD) spectra and specific rotation. The chiral higher-order conformation of the polymer was supposed to be stabilized by elongation of the repeating unit. That is, the CD spectra and the specific rotation of the polymer solution in aprotic solvents were found to be influence by the degree of polymerization until it reaches about 55. The temperature-independent and solvent-dependent nature of the CD spectra indicated that the chiral conformation of the polymer is stable at least in the range of 0−60 °C in tetrahydrofuran which disappears by addition of protic solvents such as methanol.