N-Arylated sulfoximines are privileged motifs in pharmaceuticals, natural products, and chiral ligands, yet their synthesis remains challenging. We report a readily accessible, air- and moisture-stable precatalyst, Pd(1-MeNAP)(tBuBrettPhos)OTf, that promotes the N-arylation of NH-sulfoximines with exceptional efficiency. The mild conditions (Cs2CO3, 25°C) enable a broad substrate scope, tolerating e.g. aryl chlorides with free NH, OH, and COOH groups and sensitive, drug-like heterocycles, thereby allowing late-stage functionalization beyond current systems. Mechanistic studies reveal that the methylnaphthyl substituent and non-coordinating triflate counterion cooperatively accelerate precatalyst activation via transmetalation/reductive elimination, generating the active monoligated Pd(0) species even in the presence of weakly nucleophilic sulfoximines.
Manna et al. (Wed,) studied this question.