Dimethyl Sulfoxide as a Synthon in Organic Chemistry

Dimethyl sulfoxide is generally characterized as a solvent and oxidant rather than as a substrate, building block, or synthon in organic chemistry. However, an abundance of reports have recently appeared that demonstrate dimethyl sulfoxide acting in these roles. This review article offers a comprehensive summary of the literature on this topic until the end of 2015. Synthetic transformations that have utilized the ‘C–S–C’, ‘C’, and ‘C–S’ fragments of dimethyl sulfoxide as building blocks are systematically summarized. 1 Introduction 2 History and Recent Highlights of DMSO-Based Oxidations 3 DMSO-Based Methylthiomethylation (–CH₂SMe) 4 DMSO as a One-Carbon Synthon 4.1 DMSO-Based Methylation (–Me) 4.2 DMSO-Based Methylenation (–CH₂–) 4.3 DMSO-Based Annulation/Aromatization (=CH–) 4.4 DMSO-Based Formylation (–CHO) 4.5 DMSO-Based Cyanation (–CN) 5 DMSO as Synthon for ‘S–C’ Functionalities 5.1 DMSO-Based Thiomethylation (–SMe) 5.2 DMSO-Based Methylsulfonylation (–SO₂Me) 6 Summary and Conclusions