A structure–taste study of arylsulfonyl(cyclo)alkanecarboxylic acids

Water‐Promoted Michael Addition Reaction of Sulfonyl Hydrazides and α, β‐Unsaturated Propionic Acids to 3‐Sulfone Propionic Acids

“…[12][13][14][15] The traditional dominant synthesis methods of 3-sulfone propionic acid compounds involve addition reaction of toxic mercaptan or thiophenol, followed the oxidation of sulphur atom (Scheme 1a). [16] Moreover, the addition reaction and decarboxylation reaction from sodium sulfonate and maleic anhydride in water, catalyzed by HOAc, can result in the 3sunfone propionic acids (Scheme 1b). [11] Starting from aryl boronic acid and acrylic acid, Na 2 S 2 O 5 as sulfone source, catalysed by PdCl 2 and chiral phosphine ligand, 3-sulfone propionic acids could be synthesized with excellent yield (Scheme 1c).…”

“…Given the biomedical benefit of sulfone and carboxylic acid, their preparation has been attracted continuous interest, leading to numerous attempts towards developing simple and efficient synthesis methods (Scheme 1). [12–15] The traditional dominant synthesis methods of 3‐sulfone propionic acid compounds involve addition reaction of toxic mercaptan or thiophenol, followed the oxidation of sulphur atom (Scheme 1a) [16] . Moreover, the addition reaction and decarboxylation reaction from sodium sulfonate and maleic anhydride in water, catalyzed by HOAc, can result in the 3‐sunfone propionic acids (Scheme 1b) [11] …”

A Bi(OTf)3-Promoted Hydrosulfonylation of Alkenes with Sulfonyl Hydrazides: An Approach to Branched Sulfones

“…In view of the importance of branched sulfones, we hypothesized 3-butenoic acid would undergo hydrogen sulfonylation to form the branched sulfone, for which their direct preparation from unactived olefins remains a challenge, through a base-promoted alkene isomerization …”

“…A preliminary mechanistic study revealed that double-bond migration to form the α,β-conjugated alkene is crucial for this transformation. In view of the importance of branched sulfones, 8 we hypothesized 3-butenoic acid would undergo hydrogen sulfonylation to form the branched sulfone, for which their direct preparation from unactived olefins remains a challenge, through a base-promoted alkene isomerization. 9 Therefore, we first treated p-toluenesulfonyl hydrazide [1a (TsNHNH 2 )] with 3-butenoic acid 2a in the presence of copper(II) triflate (10 mol %), 1,10-phenanthroline (1,10-Phen, 30 mol %), and cesium carbonate (Cs 2 CO 3 , 100 mol %) in acetonitrile at 100 °C for 10 h (Table 1, entry 1).…”