Copper‐Catalyzed Aerobic Oxidative NS Bond Functionalization for CS Bond Formation: Regio‐ and Stereoselective Synthesis of Sulfones and Thioethers

Abstract

A regio- and stereoselective synthesis of sulfones and thioethers by means of Cu(I)-catalyzed aerobic oxidative N-S bond cleavage of sulfonyl hydrazides, followed by cross-coupling reactions with alkenes and aromatic compounds to form the C sp 2-S bond, is described herein. N2 and H2O are the byproducts of this transformation, thus offering an environmentally benign process with a wide range of potential applications in organic synthesis and medicinal chemistry.

Effective Laboratory-Scale Preparation of Axitinib by Two CuI-Catalyzed Coupling Reactions

“…6,[13][14][15][16][17][18][19][20] CuI has been used to catalyze the C-S cross-coupling reaction because of its stability to air and good activity with or without the assistance of supporting ligands. [21][22][23][24][25][26] Compared with the above C-S cross-coupling reaction, the application of CuI in the Heck-type reaction is reported less frequently, but there are some successful examples. [27][28][29][30] A copper catalytic systems are cheaper, and easier to remove the heavy metal residues relative to palladium.…”

Recent advances in the synthesis of vinyl sulfones

“…In 2014, a methodology of preparation of vinyl sulfones by means of Cu I -catalyzed aerobic oxidative N-S bond cleavage of sulfonyl hydrazides, followed by cross-coupling reaction with alkenes to construct C sp2 -S bonds was reported by Jiang and co-workers 46 (Scheme 25). The use of aromatic and heteroaromatic alkenes as well as naphthalene led to the cross-coupling products.…”

Generation of Sulfonyl Radicals from Aryldiazonium Tetrafluoroborates and Sulfur Dioxide: The Synthesis of 3‐Sulfonated Coumarins

“…[1][2][3][4] Notably, the generation of a sulfonyl radical and its addition to unsaturated CÀC bonds (such as alkenes and alkynes) contribute much to recent advances in the synthesis of sulfones. [6,7] The single-electron oxidation of sulfinates [8] or sulfinic acids [9] and the oxidative cleavage of sulfonyl hydrazides [10] also provide efficient routes for the formation of sulfonyl radicals (Scheme 1 b). [5,6] For instance, sulfonyl radicals can be produced from their corresponding sulfonyl halides, sulfonyl selenides, sulfonyl azides, and sulfonyl cyanides in the presence of radical initiators, light, or catalysts (Scheme 1 a).…”

“…More recently, Qiu and co-workers reported a silver-promoted acylation of aryl propiolates with 2-oxoacetic acids for the synthesis of 3-acylcoumarins. Higher yields were obtained as the amount of DABCO·(SO 2 ) 2 was increased, and the employment of 2.0 equivalents of DABCO·(SO 2 ) 2 led to an improved efficiency (entries [10][11][12]. 3-Bromocoumarins and 3-acetonylcoumarins were also successfully obtained in their subsequent work, which was also thought to undergo the 5-exo cyclization and ester migration.…”