Palladium-Catalyzed Oxidative Cross-Coupling of Arylhydrazines and Arenethiols with Molecular Oxygen as the Sole Oxidant

Abstract

A highly efficient palladium-catalyzed oxidative cross-coupling of arylhydrazines and arenethiols with molecular oxygen as the sole oxidant to afford unsymmetrical diaryl sulfides has been developed. The only byproducts are nitrogen and water. A broad range of functional groups, even the reactive iodides, are tolerated and thus offer the opportunity for further functionalization.

Recent Advances in the Pd‐Catalyzed Coupling of Arylhydrazines and Ammonium Salts via C−N Bond Cleavage

“…In 2018, we described a Pd-catalyzed denitrogenative oxidative cross-coupling of aryl thiols with arylhydrazines using O 2 as an oxidant (Scheme 16). [29] This was the first time that arylhydrazines were combined with arylthiols to produce unsymmetrical diaryl sulfides in high yields. Notably, substrates with halogen substituents were compatible with the process, especially highly reactive Br and I groups; the obtained diarylsulfides offered the opportunity for further functionalization.…”

Recent developments in palladium-catalyzed C–S bond formation

“…Zhao and co-workers also discovered a palladium-catalyzed oxi- dative arylthiolation of arylhydrazines (99) with arenethiols (100) using molecular oxygen as the sole oxidant. 61 As shown in Scheme 37, in the presence of 5 mol% of Pd(OAc) 2 , PCy 3 (10 mol%), and Na 2 CO 3 (1 equiv. ), in toluene under an O 2 balloon at 100°C for 12 h, a range of unsymmetrical diaryl sulfides (101) were obtained in good to high yields.…”

One‐Pot Manganese (IV)‐Mediated Synthesis of Sulfonyl Fluorides from Arylhydrazines

“…In particular, aryl hydrazines have been successfully used for the preparation of various biologically useful compounds including indoles, indazoles, pyrazoles, and quinazolines [21] . In addition, aryl hydrazines have been widely employed as starting materials for various reactions, including carbon‐carbon and carbon‐heteroatom cross‐coupling reactions such as Suzuki coupling, Sonogashira coupling, Heck coupling, C−N bond formation, C−P bond formation, C−Se bond formation, and C−S bond formation, because they enable the generation of aryl radical intermediates [21–29] …”