Site‐Selective C−S Bond Formation at C−Br over C−OTf and C−Cl Enabled by an Air‐Stable, Easily Recoverable, and Recyclable Palladium(I) Catalyst.

Abstract: This report widens the repertoire of emerging PdI catalysis to carbon–heteroatom, that is, C−S bond formation. While Pd0‐catalyzed protocols may suffer from the formation of poisonous sulfide‐bound off‐cycle intermediates and lack of selectivity, the mechanistically diverse PdI catalysis concept circumvents these challenges and allows for C−S bond formation (S–aryl and S–alkyl) of a wide range of aryl halides. Site‐selective thiolations of C−Br sites in the presence of C−Cl and C−OTf were achieved in a general and a priori predictable fashion. Computational, spectroscopic, X‐ray, and reactivity data support dinuclear PdI catalysis to be operative. Contrary to air‐sensitive Pd0, the active PdI species was easily recovered in the open atmosphere and subjected to multiple rounds of recycling. [ABSTRACT FROM AUTHOR]