A Practical Guide for X-H Insertion Reactions with Sulfoxonium Ylides

Abstract

Sulfoxonium ylides have emerged as safer alternatives to diazo compounds for generating metal carbenes in X-H insertion reactions. However, most studies still focus on aryl ester ylides and on a relatively narrow selection of noble metal catalysts. In this work, it was investigated aryl, alkyl, and unsubstituted sulfoxonium ylides (ester, keto and amide) in X-H insertion reactions mediated by metal carbenes. A broad range of catalysts was evaluated under standardized conditions, including noble metals such as Au, Ag, Pt, Pd, Rh, Ir, and Ru, and non-noble metals such as Fe, Cu, Zn, Ni, V, Mn, Co, Zr, and Sc. For the aryl ester ylide, several catalysts promoted N-H insertions in good yields, with notable performance from Ir, Rh, Fe, Ag, Sc, and V complexes. For unsubstituted ylides, only Rh, Ir, and Ru complexes delivered satisfactory results. Based on these data, alkyl ylides were evaluated only with Ir, Rh, and Ru, showing high efficiency for Ir and Rh. The aryl keto ylide displayed distinct behavior, forming mainly the imine and 1,2-dicarbonyl products. O-H and S-H insertions were also carried out for the aryl ester ylide using different catalysts, giving yields between 10-94%.

Keywords:
sulfoxonium ylides; insertion reactions; metal-carbene; catalyst; carbon-heteroatom bond