Reductant-Controlled Access to Sulfinamides from Aliphatic Primary Amines

The conversion of primary amines into sulfinamides through formal sulfoxide (SO) insertion into stronger C-N bonds offers a challenging yet compelling approach for subtle functional group editing, in contrast with a complete functionality swap. We disclose a reductive deaminative sulfinamidation of <i>N</i>-alkylpyridinium salts with <i>N</i>-sulfinylamine, both derived from aliphatic primary amines as the common building block, to forge a C(sp³)-S bond, en route to sulfinamides. The reductant-controlled generation of primary or secondary alkyl radicals from pyridinium salts enables selective access to distinct sulfinamides with broad functional group compatibility. This operationally simple and scalable method is amenable to late-stage functionalization of various amine-containing drugs, exemplified by formal SO insertion into the C-N bond of mexiletine to deliver its sulfinamide analogue.