Carbon monoxide aliphatic 1-olefin copolymerization

The catalyst [Pd(Me-DUPHOS)(MeCN)2](BF4)2 was also effective in the alternating asymmetric copolymerization of aliphatic a-olefins with carbon monoxide [27,28]. The polymer synthesized in a CH3N02-CH30H mixture has both 1,4-ketone and spiroketal (10) units in the main chain. The propylene-CO copolymer consisting only of a 1,4-ketone structure shows [ ]D +22° (in (CF3)2CHOH), and the optical purity of the main chain chiral centers is over 90% as estimated by NMR analysis using a chiral Eu shift reagent. 

In addition to hydrogenation reactions, modular phospholane ligands are being applied in a growing rank of other useful asymmetric catalytic transformations. For instance, Jiang and Sen reported the discovery of a dicationic Me-DuPhos-Pd catalyst for the alternating copolymerization of aliphatic a-olefins and carbon monoxide (Scheme 13.21).67... 

The copolymerization of ethylene and carbon monoxide to give alternating copolymers has attracted considerable interest in both academia and industry over recent decades [1, 2]. Attention was focused on aliphatic polyketones such as poly(3-oxotrimethylene) (1) because of the low cost and plentiful availability of the simple monomers. The new family of thermoplastic, perfectly alternating olefin/ carbon monoxide polymers commercialized by Shell provides a superior balance of performance properties not found in other commercial materials the an ethylene/ propene/CO terpolymer is marketed by Shell imder the tradename Carilon . About the history of polyketones see Refs. [3-11],... 

Ethylene and other olefins can also be copolymerized with carbon monoxide to form polymers of aliphatic ketones, using transition metal catalysts, like paUadium(ll) coupled with non-coordinating anions. There are numerous reports of such catalysts in the literature. One example is a compound composed of bidentate diarylphosphinopropane ligand and two acetonitrile molecules coordinating Pd coupled with BF3 counterions. This compound, bis(acetonitrile)palladium(II)-l,3-bis(diphenyl-phosphino)propane-(tetrafluoborate), can be illustrated as follows [97] ... 

Jiang, Z. Sen, A. PaUadium(II)-catalyzed isospecific alternating copolymerization of aliphatic a-olefins with carbon monoxide and isospecific alternating coohgomerization of 1,2-disubstituted olefin with carbon monoxide. Synthesis of novel, optically active, isotactic 1,4- and 1,5-polyketones. J. Am. Chem. Soc. 1995,117,4455 67. 

D.i. Acylpalladation of Aliphatic 1-Olefins Olefin-Carbon Monoxide Copolymerization... 

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