Palladium‐Catalyzed Direct Thiolation of Aryl CH Bonds with Disulfides

Abstract

A catalytic variant of the direct thiolation of arenes, bearing directing groups, with disulfides or thiols has been developed under palladium and copper co-catalysis. Both sulfenyl moieties of the disulfide could be incorporated into the thiolated products, therefore, the reactions reached completion with only half an equivalent of disulfide, with respect to the starting arene. Experimental evidence suggested that the reaction proceeds through a Pd(II)/Pd(IV) mechanism.

Recent advances in C–S bond formation via C–H bond functionalization and decarboxylation

“…Recently, Nishihara and co-workers reported direct thiolation of aryl C-H bonds in arenes with disulfides or thiols to afford thiolated products (12a-i) (Scheme 12). 32 The reaction proceeded with ortho-selectivity attributable to the directing groups such as 2-(3-methyl)pyridyl, 2-quinolyl, 2-pyrimidyl, and bidentate 8-aminoquinoline. This protocol tolerates a variety of functional groups and substrates under mild oxidative reaction conditions.…”

“…31 Scheme 12 Nishihara's direct thiolation of arenes with diphenyl disulfide. 32 Scheme 13 Yu's thioetherification of aryl C-H bonds. 35 Patel and co-workers described an efficient route to preparing 2-aminobenzothiazoles (17a-f) from aryl isothiocyanates by Cu(OTf) 2 -catalyzed intramolecular C-H functionalization/C-S bond formation (Scheme 16).…”

Copper‐Promoted Thiolation of C(sp2)–H Bonds Using a 2‐Amino Alkylbenzimidazole Directing Group

“…Although the mechanism is unclear at this moment, based on our own observations and previous reports,, especially Stahl's work on the mechanisms of copper(II)‐mediated C–H oxidations,[19e] a C , N , N ‐pincer‐type Cu III intermediate involved in a concerted metalation–deprotonation (CMD) pathway may be reasonable (see Figure S2 in the Supporting Information).…”

Sodium Iodide (NaI)‐Catalyzed Cross‐Coupling for C−S Bond Formation via Oxidative Dehydrogenation: Cheap, Direct Access to Unsymmetrical Aryl Sulfides

“…To demonstrate the practicability of this reaction, two bioactive compound skeletons were synthesized in good yields. Classical transition-metal-catalyzed cross-coupling reactions of prefunctionalized arenes [1c, 3] (e.g.,a ryl halides) with various sulfurbased partners were mediated by palladium, [4] copper, [5] nickel, [6] iron, [7] cobalt, [8] rhodium [9] and gold. [1] Thus, the formationo fC ÀSb onds has garnered much attention.…”

“…[1] Thus, the formationo fC ÀSb onds has garnered much attention. Classical transition-metal-catalyzed cross-coupling reactions of prefunctionalized arenes [1c, 3] (e.g.,a ryl halides) with various sulfurbased partners were mediated by palladium, [4] copper, [5] nickel, [6] iron, [7] cobalt, [8] rhodium [9] and gold. Classical transition-metal-catalyzed cross-coupling reactions of prefunctionalized arenes [1c, 3] (e.g.,a ryl halides) with various sulfurbased partners were mediated by palladium, [4] copper, [5] nickel, [6] iron, [7] cobalt, [8] rhodium [9] and gold.…”