Solvent-catalyzed umpolung carbonsulfur bond-forming reactions by nucleophilic addition of thiolate and sulfinate ions to in situ-derived nitrosoalkenes in deep eutectic solvents

The low transition temperature mixture formed by lactic acid and choline chloride proved to be effective for an umpolung carbonsulfur bond formation at the α-position of α-chloro oximes. Aliphatic, aromatic, and heteroaromatic thiolate and sulfinate ions can be smoothly added to in situ-derived nitrosoalkenes affording the corresponding sulfenylated or sulfonylated adducts, respectively, in a very good yield (up to >98%). This methodology offers the advantage of working at room temperature and under air in biodegradable and cost-effective reaction mixtures, which can be used both as solvents and catalysts (20 mol %), thereby avoiding the use of anhydrous, hazardous volatile organic solvents and an inert atmosphere.

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