The first N-bromosuccinimide (NBS)-promoted transition metal-free cross-dehydrogenative esterification of carboxylic acids with dimethyl sulfoxide (DMSO) has been disclosed for formal C–O formation via Pummerer-type rearrangement. These transformations employ readily available carboxylic acids as the nucleophile and DMSO as the sulfur-containing carbon source and solvent under mild conditions, affording valuable (methylsulfinyl)methyl esters with a broad substrate scope. Furthermore, the developed protocol provides an efficient and straightforward method for the preparation of deuterated (methylsulfinyl)methyl esters by use of deuterium-labelled DMSO as the reagent.

中文翻译：

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NBS活化的DMSO对羧酸的交叉脱氢酯化反应

首次公开了N-溴琥珀酰亚胺（NBS）促进的羧酸与二甲基亚砜（DMSO）的无过渡金属交叉脱氢酯化反应，可通过Pummerer型重排形成正式的C-O 。这些转化在温和的条件下采用容易获得的羧酸作为亲核试剂，并使用DMSO作为含硫的碳源和溶剂，从而提供了具有宽泛底物范围的有价值的（甲基亚磺酰基）甲基酯。此外，通过使用氘标记的DMSO作为试剂，开发的方案为制备氘代（甲基亚磺酰基）甲酯提供了一种有效而直接的方法。