Desulfurization of Thioketals into Methylene and Methyl Derivatives: Nickel or not Nickel?

In this review, the desulfurization of thioacetals and thioketals leading to methyl and methylene derivatives is summarized through metal and metal-free methodologies. In the section concerning the use of metals for desulfurization reactions, we will be successively presenting and discussing all methods requiring Ni and Ni derivatives as reducing agents and other examples in which metals were used to generate solvating electrons as reducing species. The following section will concern the use of other desulfurizing agents as metal-hydrides (Bu3SnH, Et3SiH) and metal-free desulfurization reactions of thioketals. The functional group tolerance of the presented methods with functionalized and sensitive substrates will be discussed.