Application of sulfoxonium ylide in transition-metal-catalyzed C-H bond activation and functionalization reactions

Sulfoxonium ylides are carbene precursors and safer alternatives for highly reactive and unstable diazo compounds, and they are used extensively in the field of C-H activation. The current review is a collection of recent advancements in transition-metal-catalyzed C(sp²)-H activation using sulfoxonium ylides as precursors. The review emphasizes the use of sulfoxonium ylides as coupling partners for acylmethylation of arenes and heteroarenes. Also, it accounts for the construction of heterocycles employing sulfoxonium ylide as a coupling partner with non-innocent directing groups by C-H activation, acylmethylation followed by intramolecular cyclization in one pot or domino fashion. The review also highlights recent advances in C-H activation reactions using sulfoxonium ylide as a carbenoid-based directing group to construct carbocyclic rings. The review focuses on using sulfoxonium ylide as a coupling partner and directing group, followed by the mode of transformation, scope of the reaction, and the possible mechanistic aspect.