299464-75-8Relevant academic research and scientific papers
Chiral phosphoric acid-catalyzed asymmetric oxidation of aryl alkyl sulfides and aldehyde-derived 1,3-dithianes: Using aqueous hydrogen peroxide as the terminal oxidant
Liu, Zhao-Min,Zhao, Hua,Li, Mei-Qiu,Lan, Yu-Bao,Yao, Qi-Bo,Tao, Jing-Chao,Wang, Xing-Wang
, p. 1012 - 1022 (2012)
(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 (H2O2) 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. Copyright
