The first copper-catalyzed oxysulfonylation reaction of alkenes with dioxygen and sulfonylhydrazides for the construction of β-ketosulfones has been developed under mild conditions without any ligand or additive.

A novel and metal-free procedure has been developed for the construction of 3-sulfonated coumarins via the direct difunctionalization of alkynoates with sulfonylhydrazides. The present protocol, which simply utilizes TBAI as the catalyst and TBHP as the oxidant, provides a convenient and highly efficient approach to construct a series of sulfonated coumarins with high regioselectivity and good functional group tolerance.

A simple, efficient and catalyst-free procedure has been developed for the construction of sulfonated oxindoles via the direct arylsulfonylation of N-arylacrylamides with sulfinic acids. The present protocol, which simply utilizes cheap oxidants, readily-available starting materials, and catalyst-free conditions, provides an alternative and highly attractive approach to a series of sulfonated oxindoles with high atom efficiency and excellent functional group tolerance.