Photostimulated Reactions of Alkanethiolate Ions with Haloarenes. Electron Transfer vs. Fragmentation of the Radical Anion Intermediate

Article abstract of DOI:10.1021/jo00339a008

The photostimulated reactions of RS(1-) ions (R = methyl, n-butyl, tert-butyl, and benzyl) with haloarenes in liquid ammonia were studied.Two main products were formed: alkyl aryl sulfide and arenethiolate ions.The formation of these compounds is explained by the S_RN1 mechanism of aromatic nucleophilic substitution.The radical anion intermediate formed in the coupling of an aryl radical with an alkanethiolate ion undergoes two competing reactions: transfer of the odd electron to the substrate leading to the substitution product or bond fragmentation leading to arenethiolate ion and an alkyl radical.It is concluded that the ratio of these products depends mainly on changes in the rate of fragmentation and not on changes in the electron-transfer reaction.