Aqueous hemin catalyzed sulfonium ylide formation and subsequent [2,3]-sigmatropic rearrangements

A mild hemin catalytic system for sulfonium ylide generation via a metal carbenoid and a subsequent [2,3]-sigmatropic rearrangement reaction in aqueous solvent is well-established, with the assistance of cyclodextrin (CD) and Triton X-100. The protocol displays high catalytic activity with a broad substrate scope of aryl/alkyl allyl sulfides and diazo reagents, affording homoallyl sulfide products in up to 99% yield. Notably, this catalytic system is successful for water-insoluble allyl sulfides but ineffective for allyl amines or allyl ethers. Moreover, an unprecedented cascade reaction of sulfonium ylide formation, [2,3]-sigmatropic rearrangement and C-H insertion was reported.