An unexpected reaction of 2-alkynylaryldiazonium tetrafluoroborate with sulfur dioxide

A palladium-catalyzed coupling reaction of aryl nonaflates, sulfur dioxide, and hydrazines

A facile route to synthesise N-aminosulfonamides through a palladium-catalyzed coupling reaction of aryl nonaflates, sulfur dioxide, and hydrazines is reported. This transformation proceeds in the presence of Pd(OAc)₂/XantPhos, and TBAB in 1,4-dioxane at 80 °C, leading to the corresponding N-aminosulfonamides in moderate to good yields.

A copper(ii)-catalyzed three-component reaction of aryldiazonium tetrafluoroborates, sulfur dioxide, with alkenes

A three-component reaction of aryldiazonium tetrafluoroborates, sulfur dioxide, with alkenes catalyzed by copper(ii) bromide is developed, which provides an efficient route to (E)-alkenyl sulfones or allylic sulfones via the insertion of sulfur dioxide.

A general iodine-mediated synthesis of primary sulfonamides from thiols and aqueous ammonia

An efficient, practical and green methodology for the synthesis of primary sulfonamides has been developed. Various types of thiols can be applied as substrates and the desired sulfonamides can be obtained in good to excellent yields.

A general route to sulfones via insertion of sulfur dioxide promoted by cobalt oxide

A cobalt-promoted coupling reaction of triethoxysilanes, sulfur dioxide, and electrophiles is developed. Different electrophilic partners including alkyl bromides, iodonium salts, and electron-poor (hetero)aryl chlorides work well under the standard conditions.

Copper(i)-catalyzed sulfonylation of (2-alkynylaryl)boronic acids with DABSO

The scaffold of benzo[b]thiophene 1,1-dioxides can be easily constructed through a copper(i)-catalyzed insertion of sulfur dioxide into (2-alkynylaryl)boronic acids. The reaction proceeds via insertion of sulfur dioxide and subsequent intramolecular 5-endo cyclization.

Generation of (2-oxoindolin-3-yl)methanesulfonohydrazides via a photo-induced reaction of N-(2-iodoaryl)acrylamide, DABSO, and hydrazine

A photo-induced catalyst-free three-component reaction of N-(2-iodoaryl)acrylamide, sulfur dioxide, and hydrazine is reported. Under ultraviolet irradiation, diverse (2-oxoindolin-3-yl)methanesulfonohydrazides are generated in moderate to good yields.

Fixation of sulfur dioxide into small molecules

Recent advances in the insertion of sulfur dioxide under transition metal catalysis or metal-free conditions via a radical process are presented.

A four-component reaction of aryldiazonium tetrafluoroborates, sulfur dioxide, 1,2-dibromoethane, and hydrazines

A four-component reaction of aryldiazonium tetrafluoroborates, sulfur dioxide, 1,2-dibromoethane, and hydrazines under metal-free conditions is described, leading to 2-arylsulfonyl hydrazones. This transformation proceeds via insertion of sulfur dioxide with good functional group tolerance.

Yb(OTf)3 catalyzed [3 + 2] annulations of D–A cyclopropanes with β-oxodithioesters: a regioselective synthesis of tetrahydrothiophenes

An efficient approach to synthesis tetrahydrothiophenes was developed through the reaction of β-oxodithioesters and D–A cyclopropanes catalyzed by Yb(OTf)₃. This methodology was highly regioselective.