Optical resolution and absolute stereochemistry of trans-2,5-dimethyl-1-phenyl-1-silacyclopentane
作者:Hai-Shan Dang、Brian P. Roberts、Derek A. Tocher
DOI:10.1039/p19950000117
日期:——
chromatography and the molecular structure of the (2S,5S)-silyl ether was determined by single-crystal X-ray diffraction. Reduction of this diastereoisomer with LiAlH4 afforded (2S,5S)-(+)-DMPSC, [α]D22+27.8 (c 2.16, cyclohexane), with an estimated enantiomeric excess of >98%. The (2R,5R)-(–)-enantiomer was prepared in a similar manner using (R)-TPED as the resolving agent, which was readily recovered in
Enantioselective hydrogen-atom abstraction by homochiral silanethiyl radicals
作者:Hai-Shan Dang、Brian P. Roberts
DOI:10.1016/0040-4039(95)00566-u
日期:1995.5
(2S,5S)-trans-2,5-Dimethyl-1-phenyl-1-silacyclopentane-1-thiyl radicals abstract hydrogen enantioselectively from silicon in (±)-trans-2,5-dimethyl-1-phenyl-1-silacyclopentane to bring about kinetic resolution of the latter; the enantiomerically-enriched silyl radicals so produced are trapped by alkyl bromide to give optically active bromosilane.