The sulfonamide scaffold is widely applied in drug discovery. In recent years, there has been growing investigation on cyclic sulfonamides (sultams) as they offer much potential in combating various diseases.
This review covers advances in β-sultam synthesis via intramolecular cyclization. Ring-closure strategies enable access to strained β-sultams and functionalization, highlighting their importance in medicinal chemistry and heterocyclic design.
γ-Sultams bearing a trifluorinated ethyl- or an ene-gem-difluorinated tether were obtained from CF3-substituted N-allenamides; experimental and DFT calculations suggested that this transformation involves a 5-endo-dig cyclization on the ene-ynamide generated in situ.
Visible-light-induced three-component reactions, which were performed under extremely mild conditions without the need for any additional additives and catalysts and showed a broad substrate scope, gave the corresponding quinazoline-based hybrids in good to excellent yields.
A strategy has been developed to separate SO2 gas from other toxic gases. The cheletropic reaction between silica-supported α,β-unsaturated iminium salt LI@MOS with SO2 gas showed reversible adsorption–desorption as high as 20 mmolg−1.