Herein, we report an efficient synthesis of azaspiro[4,5]‐decanes and azaspiro[4,5]‐trienones by the radical cascade spirocyclization of N‐benzylacrylamides or N‐arylpropiolamides respectively. These reactions proceed under metal free conditions and involve in situ generation of aryl sulfonyl radicals from DABSO and aryl diazonium salts. Furthermore, a catalyst free visible light mediated protocol was developed for the sulfonylative spirocyclization of N‐aryl alkynamides using diaryliodonium salts. The utility of these protocols were justified by the excellent compatability of a wide range of functional groups, good yields and scalablity under mild conditions at room temperature.

Photocatalytically generated sulfenyl radicals were coupled with arylsulfonyl radicals at room temperature for accessing unsymmetrical organic thiosulfonates.

We report an efficient water mediated, Brønsted acid-catalyzed rearrangement of alkynyl cyclohexadienones to access meta-olefinated phenols under metal-free conditions. The reaction displayed excellent substrate scope and yields in water. Synthetic utility of the protocol was highlighted by carrying out gram scale synthesis, further functionalizations, and late stage modification. Mechanistic studies highlighted the key role of water, as the reaction proceeds via a water addition–elimination sequence on to a vinyl cation intermediate.

We hereby report a highly regio- and diastereoselective arylsulfonylation-radical cyclization-selenylation cascade of alkynyl cyclohexadienones for the facile synthesis of highly functionalized dihydrochromenones. The protocol utilizes aryldiazonium salts as aryl partners...

Herein, we report a reductive hydrazo-sulfonylative difunctionalization cascade of alkynyl cyclohexadienones employing PhTeTePh as an uncommon reducing agent. Diphenyl ditelluride is a commercially available solid with a good solubility profile in most organic solvents, and this is the first report illustrating it as a reducing agent. The protocol afforded a variety of difunctionalized dihydrochromenones and dihydrobenzofuranones in good yields under relatively mild conditions. The reactions were scalable, and mechanistic studies were conducted to probe the reaction mechanism. Additionally, photophysical studies of the products were carried out, which revealed that they had significant absorption (400–450 nm) and emission (520–570 nm) in the visible region.