Various active methylene compounds were carboxylated by employing the reagent system, 1,8-diazabicyclo(5.4.0)-7-undecene and carbon dioxide, in organic solvents or without solvent at room temperature.
The spectral changes and photoproducts which are produced on photolysis of 0-ethyl S-benzyl xanthate (BX) and the photopolymerization of vinyl monomers in the presence of BX are described. The photochemical decomposition of BX, which involves homolytic scission of the s-C (=S) bond via an intermediate, gives rise to benzyl mercaptan and carbonyl sulfide, thus serving as an efficient initiating process for polymerization. The chain-transfer const,ants for BX on photopolymerization are 7.5 for methyl methacrylate and 20.4 for styrene, resulting in 6.2 for Qt, and +0.7 for etr. The mechanisms of the chain-transfer reaction are discussed.We have previously reportedS that the polymers containing the N,N-diethyldithiocarbamate group are very effective as photosensitive resins, and that benzyl diethyldithiocarbamate and carbo-iso-propoxymethyl diethyldithiocarbamate, the model compounds for these resins, are excellent photosensitizers as well as powerful transfer agents for the polymerization of methyl methacrylate (MMA).We have, furthermore, found4 that some xanthates structurally similar to the dithiocarbamate are also photosensitizers for the polymerization of vinyl monomers.The present work has been initiated in the hope of shedding further light on the photosensitivities of xanthates, and this paper describes the photochemical behavior of 0-ethyl S-benzyl xanthate (BX), which is the model compound for the photosensitive polymer (PBX), and the photopolymerization of vinyl monomers in the presence of BX.
Copper-iron-polyphthalocyanine shows catalytic activity on the oxidation of acetaldehyde ethylene acetal with oxygen at 30°C; this catalytic activity is remarkably dependent on the atomic ratio of copper to iron ions involved and on the activation energy of the electrical conductivity of copper-iron-polyphthalocyanine. The catalytic oxidation of acetaldehyde ethylene acetal with oxygen in the presence of copper-iron-polyphthalocyanine gives, selectively, ethylene glycol monoacetate as the main reaction product, together with small amounts of ethylene glycol diacetate, ethylene glycol, acetaldehyde, and acetic acid. This catalyst is also effective in the selective oxidation of cumene and benzaldehyde ethylene acetal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.