Recent Advances in Transition-Metal-Catalyzed C–S Activation: From Thioester to (Hetero)aryl Thioether

Abstract

Carbon–sulfur bonds widely exist in natural products, pesticides, and drugs, and their activation, cleavage, and transformation via transition metal catalysis have become more and more important in organic chemistry. During the past several decades, great progress on transition-metal catalyzed carbon–sulfur activation of thioesters and their transformations has been achieved. Carbon–sulfur bonds linking to both heteroaryl and aryl groups can be cleaved to construct carbon–carbon bonds by coupling reactions or to construct carbon–hydrogen bonds by reductions. This perspective is focused on recent advances in cleavage and transformations of transition-metal-catalyzed carbon–sulfur bonds.

Palladium(ii)-catalyzed synthesis of dibenzothiophene derivatives via the cleavage of carbon–sulfur and carbon–hydrogen bonds

“…It was envisioned that the required C–H activation of the 2′-position in 1 could be achieved by a sulfur-directed cyclometallation process 11,12. With this in mind, we focused our initial effort on the development of suitable conditions for this unprecedented cyclization process involving C–S activation 9. After several experiments, we found that Pd(OAc) 2 performed as a potential catalyst for the cyclization of 1a (Table 1, entry 1).…”

“…Herein, we report a unique C–H/C–S coupling strategy for the catalytic synthesis of fused thiophene derivatives (Scheme 1d). The notable features of the reaction are as follows: (1) it does not require any reactive functionalities, such as C–X or S–H bonds; (2) it does not require an external oxidant, such as a silver salt; and (3) the reaction proceeds through the cleavage of inert C–H and C–S bonds 9. Although strong acid-mediated reaction of biphenyl sulfoxides was reported to form dibenzothiophenes through formal C–H and S–Me cleavage, its mechanism involves classical Friedel–Crafts type C–H functionalization and S–Me cleavage via the S N 2 mechanism 10…”

Katalytische, isofunktionelle Reaktionen – Erweiterung des Repertoires an Shuttle‐ und Metathesereaktionen

“…[135] Demgegenüber sind Metathesereaktionen mit aromatischen Thioestern selten, ungeachtet ihrer weiten Verbreitung in den Molekularwissenschaften. [137] Ein Metatheseprozess,indem einer der Substituenten gegen einen anderen ausgetauscht werden kann, wäre komplementärz uK reuzkupplungsmethoden, da er eine einfache Diversifikation der Thioether ermçglichen würde.E sg ab vereinzelte Berichte über C-S-Metathesereaktionen, [138] aber die erste allgemeine Methode wurde 2017 von der Gruppe um Morandi publiziert. [137] Ein Metatheseprozess,indem einer der Substituenten gegen einen anderen ausgetauscht werden kann, wäre komplementärz uK reuzkupplungsmethoden, da er eine einfache Diversifikation der Thioether ermçglichen würde.E sg ab vereinzelte Berichte über C-S-Metathesereaktionen, [138] aber die erste allgemeine Methode wurde 2017 von der Gruppe um Morandi publiziert.…”

Synthesis of Disubstituted Dithioethers: tert-Butoxide Promoted Elimination/Ring Opening of 1,3-Dithianes Followed by Palladium-Catalyzed C–S Bond Formation

“…Workup of the reaction resulted in a red brown oil (0.3359g, 86%). 1 Phenyl (3-(styrylthio)propyl)sulfane (9). The title compound was prepared using the general procedure with bromobenzene (0.104 mL, 1.0 mmol).…”