Synthesis of heteroaryl containing sulfides via enaminone ligand assisted, copper-catalyzed C–S coupling reactions of heteroaryl thiols and aryl halides

Mono- and Dinuclear α-Diimine Nickel(II) and Palladium(II) Complexes in C–S Cross-Coupling

“…Moreover, the need for harsh reaction conditions profoundly limits the C−S coupling of alkyl and heteroaryl thiols for generating medicinally important heteroaryl compounds. 14,20,32,33 However, Ni B-1 and Pd B-1 manifested promising performance in milder reaction settings.…”

“…In contrast, well-defined Ni B-1 and Pd B-1 catalytic systems have afforded excellent yields in aerobic reaction settings. Moreover, the need for harsh reaction conditions profoundly limits the C–S coupling of alkyl and heteroaryl thiols for generating medicinally important heteroaryl compounds. ,,, However, Ni B-1 and Pd B-1 manifested promising performance in milder reaction settings.…”

“…14,19 Consequently, harsh reaction conditions significantly hinder the C−S coupling of alkyl-substituted thiols 20,32 and pharmaceutically important heterocycles. 14,33 Photoredox catalysis has attracted attention as a possible solution, but widely used iridium-and ruthenium-based photosensitizers are expensive and have inadequate substrate scope. 22 To overcome the existing challenges in transition-metalcatalyzed C−S coupling, the influence of steric topography around the metal center and the ligand bite angle has been studied.…”

“…Recently, Ni-based systems have gained popularity for their environmental friendliness, cost-effectiveness, and decreased tendency to deposit metallic nanoparticles . However, both Pd- and Ni-catalytic systems continue to demand high catalyst loading (5–50 mol %), ,,− , high temperature (100–150 °C), ,,,,,,, expensively designed ligands, , additives, ,, and longer reaction times (12–72 h). − ,− ,,,,,, Previously reported systems that do well concerning these issues, such as Venkanna et al’s Ni-pyrrole system or Buchwald et al.’s Pd-monophosphine system, still suffer from the requirement of using glovebox conditions. , Consequently, harsh reaction conditions significantly hinder the C–S coupling of alkyl-substituted thiols , and pharmaceutically important heterocycles. , Photoredox catalysis has attracted attention as a possible solution, but widely used iridium- and ruthenium-based photosensitizers are expensive and have inadequate substrate scope …”

Gold nanoparticle catalyzed intramolecular C–S bond formation/C–H bond functionalization/cyclization cascades

“…1,2 In traditional methods, the cross-coupling of aryl halides with thiols/disuldes has become one of the dominant methods for the construction of C-S bonds. [3][4][5][6][7] However, the prefunctionalization of the starting materials in this protocol limited its application. More recently, combination of selective, catalytic activation of C-H bonds with functionalization to form C-S bonds has been a subject of particular interest in recent years.…”