Decarboxylative radical addition to vinylsulphones and vinylphosphonium bromide: Some further novel transformations of geminal (pyridine-2-thiyl) phenylsulphones.
摘要:
Irradiation of O-acyl derivatives 1 of N-hydroxy- 2-thiopyridone with visible light in the presence of phenyl vinyl sulphone or vinyl triphenylphosphonium bromide leads to the corresponding adducts 8 and 9 which can undergo a wide variety of further transformations.
Radical decarboxylative alkylation of tartaric acid
作者:Derek H.R. Barton、Alice Gateau-Olesker、Stephan D. Géro、Brigitte Lacher、Catherine Tachdjian、Samir Z. Zard
DOI:10.1016/s0040-4020(01)81288-6
日期:1993.5
Newderivatives of L-(+)-tartaricacid have been synthesized from the monomethyl-2,3-O-isopropylidene (R,R)-(+)-tartrate by visible light photolysis of its N-hydroxy-2-thiopyridone ester derivative in presence of activated alkenes. The carbon radical generated at the dioxolane ring adds stereoselectively to olefins to give the addition products with retention of configuration.
Radical addition to vinyl sulphones and vinyl phosphonium salts
作者:Derek H.R. Barton、Hideo Togo、Samir Z. Zard
DOI:10.1016/s0040-4039(01)84596-2
日期:——
Alkyl radicals, derived from decarboxylation of carboxylic acids, add readily to phenyl vinyl sulphone and vinylphosphonium bromide. The adducts may be further converted into a variety of useful synthetic intermediates.