Enantioselective alternating copolymerization of carbon monoxide with ω undecylenic acid was carried out using cationic palladium catalyst modified by 1,4 3,6 dianhydro 2,5 dideoxy 2,5 bis(diphenylphosphino) L iditol (DDPPI). The chiral diphosphine was proved to be effective in the enantioselective copolymerization. The pure poly(1,4 ketone) was obtained by dissolving the copolymer containing spiroketal and 1,4 ketone units in 1,1,1,3,3,3 hexafluoro 2 propanol and reprecipitating with methanol. Optical rotation, elemental analysis, spectra of 1H, 13 C NMR and IR showed that our copolymer was an optically active, isotatic, alternating poly(1,4 ketone) structure. The copolymerization was carried out at 45 ℃ for 20 h. Molecular weight: n=1.1× 10 4 versus polystyrene, w/ n=1.84. Molar optical rotation: 20 589 =+43°(CH 3COOC 2H 5, 5.0 mg/mL). The productivity of the copolymer of ω undecylenic acid with carbon monoxide was 40.6 g copolymer/(g Pd·h).
Metal clusters have been suggested as active catalysts in a variety of homogeneous catalytic reactions. In this paper the cyclopropanation of styrene with ethyl diazoacetate is catalyzed by metal cluster (μ 3 S)Fe 2CoCu(PPh 3) 2 (CO) 8 for the first time. Expenimental results show that toluene as solvent, Styrene/EDA=4, EDA/Cat.=100, , 30 ℃ and 24 h are the best conditions. After reaction, the catalyst was isolated and characterized.
