The mechanisms of the reactions of substituted phenylalkynes with brominating agents (especially tribromide ion) and aryl sulfenyl halides: Product, stereochemical, kinetic and isotope effect studies.

摘要

Addition of tetrabutylammonium tribromide (TBAT) to p-substituted phenyl-acetylenes spanning a wide range of Hammett sigma values (i.e. p-MeO-, p-MeS-, p-PhO-, p-Me-, p-t-Bu-, unsubstituted, p-F-, p-Cl-, p-CF;Carbon-14 kinetic isotope effects (KIE's) have been observed in the ;The kinetics of addition of 2,4-dinitrobenzensulfenyl chloride (2,4-DNBSC) to p-MeO-, p-Me-, unsubstituted, p-Cl-, and p-CF;The product stereochemistry varied as a function of the para substituents. In the presence of strong EDG's (p-MeO-, p-MeS-, p-PhO-), as well as strong EWG's (p-CF