α-Diazo-β-oxosulfones as Partners in the Wolff 1,2,3-Triazole Synthesis and the Wolff Rearrangement in the Presence of Aromatic Amines

Article abstract of DOI:10.1002/ejoc.201900698

The readily available α-diazo-β-oxosulfones have been employed, for the first time, in the Wolff cyclocondensation with aromatic amines promoted by 1.5-fold excess of TiCl₄. The reaction was found to be general (as illustrated by 15 product examples) and resulted in moderate yields of medicinally relevant sulfonyl 1,2,3-triazoles. Excluding the Lewis acid promoter resulted in a clean and high-yielding formation of α-sulfonyl acetanilides resulting from the thermal Wolff rearrangement and trapping of the ketene intermediate with an aniline molecule.