Consecutive Approach to Alkenes that Combines Radical Addition of Phosphorus Hydrides with Horner−Wadsworth−Emmons-Type Reactions
作者:Mark P. Healy、Andrew F. Parsons、James G. T. Rawlinson
DOI:10.1021/ol050292e
日期:2005.4.14
the phosphonothioate and reaction with a ketone, offers a concise one-pot approach to substituted alkenes. This novel method, which can incorporate alkylation or acylation steps, can be applied to the stereoselective formation of sterically hindered tri- and tetrasubstituted alkenes.
Sulfur‐based olefination with Horner–Wadsworth–Emmons‐type mechanism is systematically studied. Nonstabilized and semistabilized carbanion precursors react with carbonyl compounds giving good yields of olefins, and for the latter reagents E isomers of alkenes predominate.
A refined verson of the Meyers' modification of the RambergâBäcklund reaction employing the reagent alumina-supported KOHâCBr2F2âButOH allows α- and αâ²-hydrogen-bearing sulfones of various structural types to be converted into alkenes.