Transition metal catalysed direct sulfanylation of unreactive C–H bonds: an overview of the last two decades

Abstract

Transition metal catalysed direct sulfanylations of unreactive C-H bonds have become a unique and straightforward synthetic strategy in late-stage C-S bond formation of relevant complex molecules. Such transformations have represented...

Directing Group Assisted Copper‐Catalyzed C−H sulfanylation of Alkenyl Carbonyl Compounds with Disulfides

“…In spite of 8‐aminoquinoline can stabilized high‐valent copper species, the Cu(III) intermediate C simultaneously undergoes reductive elimination to provide the sulfanylation product 3 a , together with the Cu(I) species. As the final step, oxidation of Cu(OAc) 2 would regenerate the CuOAc to resume the catalytic cycle [7d,8b,c] …”

Recent advances in selective mono-/dichalcogenation and exclusive dichalcogenation of C(sp2)–H and C(sp3)–H bonds

“…Over the past two decades, the direct chalcogenation of C-H bonds has evolved as a straightforward, atom-and step-economical method for the preparation of chalcogenated compounds including organyl sulfides, selenides, sulfones, trifluoromethylthioethers, thiocyanates and selenocyanates. [57][58][59][60][61][62][63][64] A variety of transition-metal-catalyzed/mediated chelationassisted C-H chalcogenation, along with directing group-free C-H chalcogenation of electron-rich (hetero)arenes and deprotonative chalcogenation of electron-deficient (hetero)arenes 65 have been reported through transition-metal-catalyzed/ mediated, 58,59,[66][67][68][69] metal-free, 29,[70][71][72][73] photocatalytic or electrochemical 60,63 approaches. For instance, in 2017, Ackermann and coworkers disclosed a copper-catalyzed chelation-assisted C2-H chalcogenation (S, Se) of indoles and C7-H chalcogenation (S, Se) of indolines with diaryl dichalcogenides through an additive-free approach under aerobic reaction conditions.…”

Pd-catalyzed site-selective C(sp2)–H chalcogenation of amino acids and peptides using a picolinamide auxiliary

“…Recently, transition-metal-catalyzed chelation-assisted direct C-H bond activation has appeared as a powerful and effective synthetic strategy for the construction of C-S bonds. [90][91][92][93] In this regard, pioneering work was carried out by Yu and co-workers on copper-catalyzed thioetherification of 2-phenylpyridine using disulfide or thiol as a thiolating agent. 94 Later, the same type of synthesis was elegantly investigated by Ackermann, [95][96][97] Glorius, 98 Shi, 99 Daugulis, 100 and others, [101][102][103][104][105][106][107][108][109][110][111][112] employing various directing groups using transition metal catalysts (Cu, Pd, Ni, Ru, Rh and Co) to achieve comparable efficiencies.…”