Palladium-Mediated Polymerization of Bifunctional Diazocarbonyl Compounds: Preparation of Crosslinked Polymers by Copolymerization of Bi- and Monofunctional Diazocarbonyl Compounds

Pd-mediated copolymerization of bifunctional diazocarbonyl compounds, 1,1'-bis(diazoacetyl)ferrocene 2, 4.4'-bis(diazoacetyl)biphenyl 5, and bis(4-diazoacetylplienyl)dimethylsilane 6, with monofunctional diazoketones, (E)-1-diazo-3-nonen-2one 3 and (E)-1-diazo-4-phenyl-3-buten-2-one 4, and ethyl diazoacetate 7 was examined in order to prepare a new type of crosslinked polymer. Although copolymerization of 2 with 3 and 4 proceeded in the presence Of PcCl(2)(MeCN)(2), the products were soluble in CHCl(3) and their M(n)s were rather low irrespective of the feed ratio of the comonomers, probably because Of the occurrence of intramolecular cyclization of two diazoacetyl groups in 2. On the other hand, copolymerization of 5 and 6 with 3, 4, and 7 with relatively high feed ratios of the bifunctional monomers afforded products insoluble in CHCl(3), which suggested the formation of crosslinked polymers. In addition, Pd-mediated (co)polymerization of monofunctional diazoacetylferrocene 1, monofunctional counterpart to 2, was examined, resulting in the formation of a new type of ferrocene-containing polymer.