VINYL PHOSPHONIUM COPOLYMER

As anticipated, upon reaction of this polymeric ester under hydrogen with phosphonium iodide, the poly(methacrylic acid) which had formed in an 84% yield showed no optical activity. When the same ester was copolymerized with three molar equivalents of maleic anhydride, the resulting ester-anhydride copolymer had an optical rotation of [hydrogen with phosphonium iodide, the resulting polymethacrylic acid had an optical rotation of = +23° (Note the reversal of the optical rotation in this case.) This appears to have been the first demonstration of a case of asymmetric induction during vinyl polymerization. 

This synthetic method has two steps the first step involves synthesising the polymer and the second includes modification with active groups. Some monomers generally used to form the backbone of homopolymers or copolymers include vinyl benzyl chloride, methyl methacrylate, 2-chloroethyl vinyl ether, vinyl alcohol and maleic anhydride. The polymers are then activated by anchoring antimicrobial groups, such as phosphonium salts, ammonium salts or phenol groups, via quaternisation, chloride substitution or anhydride hydrolysis. 

In 2007, Nozaki et al. reported that the mixture of Pd(dba)2 and phosphonium sulfonate (la, lb) catalyzed the alternating copolymerization of vinyl acetate with CO (Scheme 12, top). The alternating structure of the obtained copolymers was unambiguously confirmed by NMR analyses and MALDI-TOF mass analysis. However, head-to-tail selectivity was found to be less controlled, which suggests that VAc insertion into the acyl-palladium bond may occur in both the 2,1-and 1,2-mode. The productivity was up to 3.0gmmor h" and the molecular weight (AfJ was up to 38 000. 

---