C(sp2) –H Sulfonylmethylation of (Hetero)arenes Using Tetramethylolglycoluril as a Methylene Surrogate

Abstract

A transition metal-free and catalyst-free strategy for the sulfonylmethylation of heteroarenes has been developed using tetramethylolglycoluril as a nontoxic in situ C1 source and sodium sulfinates. This reaction takes place in HFIP, a versatile solvent that can be recycled and reused, making this protocol cost-effective and environmentally friendly. This approach is applicable to a range of medicinally relevant heteroarenes, including pyrazolo[1,5-a]pyrimidines, imidazo[1,2-a]pyridines, imidazo[2,1-b]thiazole, indoles, 2-naphthol, and N,N-dimethylaniline. Tetramethylolglycoluril acts as an in situ C1 source and is required in substoichiometric amounts. Mechanistic studies suggest an ionic mechanism for the reaction. Easy operation, broad substrate scope, and reusable solvent are a few advantages of the developed methodology. © 2026 American Chemical Society