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Chiral Phosphoric Acid‐Catalyzed Asymmetric Oxidation of Aryl Alkyl Sulfides and Aldehyde‐Derived 1,3‐Dithianes: Using Aqueous Hydrogen Peroxide as the Terminal Oxidant

作者:Zhaomin Liu, Hua Zhao, Mei‐Qiu Li, Yu‐Bao Lan, Qi‐Bo Yao, Jing‐Chao Tao, Xing‐Wang Wang · 发表于:Advanced Synthesis & Catalysis · 年份:2012 · DOI:10.1002/adsc.201100810 · 被引用次数:53 · 研究领域:Asymmetric Synthesis and Catalysis、Oxidative Organic Chemistry Reactions、Synthesis and Catalytic Reactions

Abstract ( R )‐1,1′‐Binaphthyl‐2,2′‐diol ( R ‐BINOL) derived chiral phosphoric acids have been explored as organocatalysts for the asymmetric oxidation of a series of aryl alkyl sulfides and 1,3‐dithianes derived from aldehydes with aqueous hydrogen peroxide (H 2 O 2 ) as the terminal oxidant. The enantiomerically enriched sulfoxides are obtained in moderate to excellent yield (up to 99%) with excellent diastereoselectivity (up to >99:1 dr ) and moderate to good enantioselectivity (up to 91:9 er ). In particular, the present protocol stereoselectively provides an efficient access to enantiomerically enriched aryl alkyl sulfoxides and dithioacetal mono‐sulfoxides, which strictly restrains the formation of the undesirable by‐products: sulfones or disulfoxides. The tracking experiments also verify that this approach proceeds via a direct sulfoxidation process, instead of a kinetic resolution route by overoxidation of the resulting sulfoxides.