Hybrid silarylene polysiloxanes incorporating chiral BINOL entities: a new class of polymer with main chain chirality

We describe the synthesis of four new chiral silylated (R)-BINOL precursors by coupling of lithiated BINOL intermediates with chlorosilanes. These chiral precursors were submitted to different polycondensation procedures to give silarylene polysiloxanes A-D with main chain chirality: either by hydrolysis-polycondensation of the bis-chlorosilane precursor I or by Pd-catalyzed cross-dehydrocoupling of bis-hydrosilanes II, III and IV. Both monomers and polymers were characterized by NMR. FT-IR, circular dichroism and polarimetry. Polymers with molecular weights of up to 30,200 gmol(-1) were obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.