A Practical Source of Chlorodifluoromethyl Radicals. Convergent Routes to gem-Difluoroalkenes and -dienes and (2,2-Difluoroethyl)-indoles, -azaindoles, and -naphthols
摘要:
The preparation of O-octadecyl-S-chlorodifluoromethyl xanthate from chlorodifluoroacetic acid and its use as a convenient source of chlordifluoromethyl radicals is described. This reagent may be used to access gem-difluoroalkenes and -dienes, as well as (2,2-difluoroethyl)-indolines, -indoles, and -naphthols.
The first examples of directsynthesis of γ-thiolactones by addition of a thiolactone-based radical are described. Mono- and bis-γ-thiolactones can be obtained by a dilauroyl peroxide initiated addition of thiolactone xanthate to various alkenes and α,ω-dienes. The process is modular and exhibits a high functional group tolerance.
A Convenient Metal-Free Reagent for the Generation and Capture of Trifluoromethanethiol
作者:Shi-Guang Li、Samir Z. Zard
DOI:10.1021/ol403038f
日期:2013.11.15
0-Octadecyl-S-trifluorothiolcarbonate is a cheap and storable crystalline source of trifluoromethanethiol that can be prepared in two steps on a multigram scale from trifluoroacetic anhydride and sodium 0-octadecyl-dithiocarbonate (xanthate). It reacts directly with gramines or with alpha-bromoketones and -esters in the presence of KF and pyrrolidine to give the corresponding trifluoromethyl sulfides in generally high yield.