Recent Advances in the Synthesis of Sulfonylureas

Abstract

Sulfonylureas are employed in a variety of applications including use as drugs to treat type II diabetes and as plant growth regulators or herbicides. Traditionally, the synthesis of sulfonylureas has been accomplished either by the treatment of sulfamides with isocyanates in the presence of a base or through sulfonamides conversion into N-sulfonyl isocyanates or N-sulfonyl carbamate derivatives which provide the corresponding sulfonylureas upon treatment with amines. Both approaches are severely limited by the weak nucleophilicity of sulfamides and by the difficulty in synthesizing and handling isocyanate species. Such a drawback could be mitigated by the emergence of protocols establishing the labile electrophilic functional groups in situ so that their coupling with nucleophilic partners takes place in one-pot. Recently, the development of environmentally friendly methods to prepare sulfonylurea containing compounds without using harmful reagents has attracted considerable attention. The aim of the minireview is to explore the different protocols emerged in the literature to generate sulfonylureas giving importance to the reaction mechanisms of crucial synthetic steps.

Carboxylic Acid Bioisosteres in Medicinal Chemistry: Synthesis and Properties

“…In the rst route (route 1, Figure 19), the SN-C bond is formed either by treatment of a sulfonamide with an isocyanate or activated carbamoyl in the presence of a base. Because the classical syntheses of isocyanates are based on the highly toxic and volatile phosgene, more environmentally friendly protocols have been developed in which isocyanates are generated in situ [133]. A convenient method concerns the isocyanation of sterically hindered amines with di-tert-butyl dicarbonate (Boc 2 O) in the presence of a catalytic amount of DMAP.…”

Review on Asymmetric Catalysis Employing 5H‐Oxazol‐4‐Ones as α‐Hydroxy Carboxylic Acid Surrogates

“…Enantioselective carbon‐sulfur bonds can be introduced via different strategies. Among them, the asymmetric sulfa‐Michael reaction was one of the most convenient and most explored reactions [83–86] . On the other hand, asymmetric sulfenylation reactions are relatively less explored where sulfur acts as an electrophile [87–89] …”

“…Among them, the asymmetric sulfa-Michael reaction was one of the most convenient and most explored reactions. [83][84][85][86] On the other hand, asymmetric sulfenylation reactions are relatively less explored where sulfur acts as an electrophile. [87][88][89] A novel asymmetric α-sulfenylation of 5H-oxazol-4-ones to N-(sulfenyl)succinimides 158 catalyzed by cinchona alkaloid-derived squaramide was successfully established in 2014, [90] to incorporate CÀ S bond at 5-position of oxalactims with excellent enantioselectivity (Scheme 56).…”

Photocatalyzed Production of Urea as a Hydrogen–Storage Material by TiO2–Based Materials

“…Approximately 90% of urea is used as a fertilizer, and the remaining percentage represents its uses as an additive in different industries. Urea can be used as a ruminant feed additive [1,2] or chemically synthesized to make urea-based herbicides or pesticides [3][4][5]. Other non-fertilizer uses of urea include manufacturing plastic materials, additives in fire retardants, tobacco products, some wines, and the cosmetic industry [6].…”