Sulfonyl radicals generated from sulfonylhydrazides by the Bu(4)NI-tert-butyl hydroperoxide (TBHP) catalysis system underwent addition to a variety of α-methyl styrene derivatives to give the corresponding allylic sulfones. This selective allylic sulfonylation is metal-free, operationally simple, and environmentally friendly.

A catalytic system consisting of KI, 18-crown-6, and TBHP for arylsulfonylation of activated alkenes with sulfonylhydrazides as sulfonyl precursor is described. This protocol provides a practical and environmentally benign method for the construction of sulfonated oxindoles in water.

Halosulfonylation of terminal alkynes was achieved with sulfonylhydrazides as the sulfonyl precursor and inexpensive iron halide as halide source in the presence of TBHP, allowing the regio- and stereoselective generation of (E)-β-chloro and bromo vinylsulfones.

A practical and environmentally friendly strategy for generating alkoxycarbonyl radicals from readily available carbazates under metal-free conditions has been developed. In the presence of tetrabutylammonium iodide and tert-butyl hydroperoxide, 2-isocyanobiphenyls smoothly underwent radical alkoxycarbonylation with carbazates to afford phenanthridine-6-carboxylates.

The formation of free radicals using visible light as the energy source is of great synthetic value. Despite advances in the photoredox catalysis process using expensive Ir and Ru complexes or organic dyes, the discovery and employment of photocatalysts based on alternative, abundant, and inexpensive metal salts remain highly desired. Herein, the visible-light-induced decarboxylation of α-imino-oxy acids for the generation of iminyl radicals has been accomplished using nontoxic and inexpensive CeCl3·7H2O as the photocatalyst via the LMCT process. The iminyl-radical-mediated C–C cleavage/amination and alkene iminoamination have been achieved within this catalyst system.