Synthesis of new N/S-containing compounds by Pd-catalyzed tandem reactions

Two methodologies to access N/S-containing compounds via palladium-catalyzed domino reactions starting from sulfanylated N-propargyl benzimidazole derivatives are described. The first one involves a cyclocarbopalladation/reduction process and leads to medium-sized N,S-heterocycles with a stereodefined exocyclic double bond. The second one is a tandem process consisting in a Suzuki − Miyaura coupling, a desulfenylative coupling, and a totally regio/stereoselective hydrothiolation of the triple bond, which enables the reincorporation of the sulfenyl moiety into the product structure.