caa a22 4500 378923102 CHVBK 20180305123610.0 cr unu---uuuuu 161128e20040101xx s 000 0 eng 10.1351/pac200476030541 doi (NATIONALLICENCE)gruyter-10.1351/pac200476030541 Nozaki K. Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Asymmetric catalytic synthesis of polyketones and polycarbonates [Elektronische Daten] [K. Nozaki] Two examples are presented for the synthesis of optically active polymers with main-chain chirality from achiral monomers using chiral metal-complexes as catalysts. Asymmetric alternating copolymerization of α-olefins with carbon monoxide provided optically active polyketones when catalyzed by an (R,S)-BINAPHOS-Pd complex. From propene and CO, highly isotactic polyketone with high enantioselectivity (>97 % like diad and >95 % ee). Spectroscopic and theoretical studies revealed that the olefin insertion is the key step for the enantiofacial selection and that this step takes place at cis to the phosphine part of (R,S)-BINAPHOS. The catalyst is applicable not only to propene/CO but also to styrene/CO, which enabled the first asymmetric terpolymerization of propene/styrene/CO. The catalyst tolerates funational groups such as fluorocarbons and a nitrile group so that they can be incorporated in the side chain. Optically active polycarbonate was also synthesized by the alternating copolymerization of cyclohexene oxide with carbon dioxide via the desymmetrization of the meso-epoxide. Dinuclei zinc species prepared from diethylzinc, ethanol, and α,α'-diphenylprolinol, was revealed to be the real active species. © 2013 Walter de Gruyter GmbH, Berlin/Boston Pure and Applied Chemistry De Gruyter 76/3(2004-01-01), 541-546 0033-4545 76:3<541 2004 76 pac https://doi.org/10.1351/pac200476030541 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1351/pac200476030541 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Nozaki K. Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan NATIONALLICENCE 773 0- Pure and Applied Chemistry De Gruyter 76/3(2004-01-01), 541-546 0033-4545 76:3<541 2004 76 pac CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter