Desulfurization with nickel and cobalt boride: scope, selectivity, stereochemistry, and deuterium-labeling studies
摘要:
A variety of organosulfur compounds containing alkylthio and arylthio groups underwent reductive desulfurization under notably mild conditions when treated with nickel boride, generated in situ from nickel chloride hexahydrate and sodium borohydride in methanol-THF(3:1). Phenyl,chloro, and ester groups are not reduced under these conditions, while iodo, bromo, nitrile, aldehyde, ketone, cyclopropane, and olefinic functions are reduced either completely or partially. Deuterium-labeling studies indicate that the hydrogen that is incorporated into the product originates from both the sodium borohydride and the protic solvent, suggesting the intermediacy of dihydrogen. The epimers 3alpha- and 3beta-(phenylthio)cholestane afforded 3alpha- and 3beta-deuteriocholestane, respectively, demonstrating that the reaction proceeds with retention of configuration. The method may thus be employed for the stereospecific preparation of deuterated products from organosulfur compounds. Arguments are presented in support of a tentative mechanism involving an oxidative addition-reductive elimination sequence via a nickel hydride intermediate.
Method for preparing sulfone or sulfoxide compound
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:US20030171589A1
公开(公告)日:2003-09-11
There is provided a method for preparing a sulfone or sulfoxide compound, characterized in that a sulfide compound is allowed to react with hydrogen peroxide in the presence of a metal oxide catalyst formed by the reaction of hydrogen peroxide with at least one metal or metal compound selected from tungsten metal; molybdenum metal; a tungsten compound comprising tungsten and a Group IIIb, IVb, Vb, or VIb element exclusive of oxygen; and a molybdenum compound comprising molybdenum and a Group IIIb, IVb, Vb, or VIb element exclusive of oxygen.
INITIATOR SYSTEM FOR CATIONIC POLYMERIZATION AND POLYMERIZATION METHOD USING SAME
申请人:China Petroleum & Chemical Corporation
公开号:EP2481760A1
公开(公告)日:2012-08-01
The present invention discloses an initiating system for cationic polymerization and a polymerization process. The present application relates to an initiating system for cationic polymerization of cationic-polymerizable monomers, and a process for cationic polymerization of cationic-polymerizable monomers by using the initiating system. The present invention particular involves an initiating system for cationic polymerization of cationic-polymerizable monomers in an aqueous reaction medium, and a process for cationic polymerization of cationic-polymerizable monomers by using the initiating system in an aqueous reaction medium.
ISOOLEFIN POLYMERS AND PROCESS FOR PREPARING THE SAME
申请人:Wu Yixian
公开号:US20120238715A1
公开(公告)日:2012-09-20
The present invention relates to isoolefin polymers and process for preparing the same. The present invention especially discloses a polymerization process for the cationic polymerization of isoolefin monomers in an aqueous reaction medium, and isoolefin polymers obtained by such process. In one embodiment, the present invention relates to a polymerization process for the cationic polymerization of isoolefin monomers in an aqueous reaction medium, and isoolefin polymers obtained therefrom. In another embodiment, the present invention relates to a dispersion polymerization process for the cationic copolymerization of isoolefins with conjugated or non-conjugated diolefins and/or vinyl aromatic compounds, and copolymers obtained therefrom.