Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts
Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts
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DOI：
10.1002/chem.201505109
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发表时间：
2016-04-18
影响因子：
4.3
通讯作者：
Shimizu, Ken-ichi
中科院分区：
文献类型：
--
作者：
Siddiki, S. M. A. Hakim;Touchy, Abeda Sultana;Shimizu, Ken-ichi
碳载Pt纳米颗粒（Pt/C）被发现是有效的非均相催化剂，用于在砜和KOtBu存在下在无氧化剂条件下醇的直接Julia烯烃化。伯醇，包括芳基、脂肪族、烯丙基和杂环醇，分别与二甲基砜和芳基烷基砜进行烯化反应，得到端烯烃和内烯烃。仲醇用二甲基砜进行亚甲基化。在2.5bar的H-2、H-相同的反应体系下，醇OH基团转化为烷基基团是有效的。末端烯化体系的结构和机理研究表明，Pt-0网站上的Pt金属颗粒负责限速脱氢的醇和KOtBu可以去质子化的砜试剂。Pt/C催化剂在烯烃化反应后可重复使用，与以往报道的方法相比，该方法具有更高的转化数（TON）和更宽的底物范围，证明了该方法的高催化效率。
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 2.5bar H-2,H- 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.