Chapter 2 Homolytic processes at sulfur

Abstract

Publisher Summary This chapter provides by means of literature examples, a guide to the use of homolytic reactions at sulfur in synthesis. The chapter discusses reactions of sulfur-centered radicals such as thiyl radicals, sulfinyl radicals, and sulfonyl radicals. The use of thiyl radicals in synthesis requires that the precursor should be compatible with as wide a range of functional groups as possible and should be capable of providing a smooth, controlled flow of radicals. Like thiyl radicals, sulfonyl radicals are generally considered to be electrophilic in nature. The chapter discusses generation of alkyl radicals from organosulfur groups such as thiols, sulfides, alkyl aryl sulfides, sulfones, and thiocarbonyl groups. The desulfurization of thiols with tin hydrides has been described. The cleavage of alkyl aryl sulfides with stannanes is not an efficient reaction unless a stabilized radical is generated. Sulfonyl radicals undergo slow loss of sulfur dioxide to give alkyl radicals. The chapter describes the formation of carbon-sulfur bonds by the reaction of carbon-centered radicals with sulfur functional groups.