title: Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.
abstract: Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method.
authors.affiliation: Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Katsura, Kyoto, 615-8520, Japan.
authors.forename: S M A Hakim
authors.initials: SM
authors.lastname: Siddiki
authors.affiliation: Institute for Catalysis, Hokkaido University, N-21, W-10, Sapporo, 001-0021, Japan.
authors.forename: Abeda Sultana
authors.initials: AS
authors.lastname: Touchy
authors.affiliation: Institute for Catalysis, Hokkaido University, N-21, W-10, Sapporo, 001-0021, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kon
authors.affiliation: Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Katsura, Kyoto, 615-8520, Japan. kshimizu@cat.hokudai.ac.jp.|Institute for Catalysis, Hokkaido University, N-21, W-10, Sapporo, 001-0021, Japan. kshimizu@cat.hokudai.ac.jp.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Shimizu
keywords: alcohols; heterogeneous catalysis; olefination; platinum; sulfones