Solvent-mediated switching between oxidative addition and addition-oxidation: access to β-hydroxysulfides and β-arylsulfones by the addition of thiols to olefins in the presence of Oxone

The reaction between aryl olefins and thiols in the presence of Oxone in toluene-water (9 : 1, v/v) affords beta-hydroxy-2-arylethyl aryl sulfides smoothly by the interception of intermediary thiyl radicals with aryl olefins; the former are generated by the oxidation of thiols with Oxone in a biphasic medium. However, the change of the solvent system to acetonitrile-water facilitates a nonradical and concerted pathway leading to 2-arylethyl aryl sulfones exclusively via a tandem click reaction followed by oxidation. In essence, 'oxidative addition' is facilitated in a toluene-water medium, while 'addition-oxidation' is promoted in acetonitrile-water. Given that Oxone is readily available, environmentally benign, and cheap, solvent-mediated switching constitutes facile and direct access to two disparate products, namely, beta-hydroxy-2-arylethyl aryl sulfides and 2-arylethyl aryl sulfones.

Automated summary

This study investigated the reaction pathways of aryl olefins and thiols in the presence of Oxone in different solvent systems, revealing two distinct reaction pathways leading to the synthesis of two different products.