Rhodium‐Catalyzed Oxidative Coupling Reaction of Isocyanides with Alcohols or Amines and Molecular Oxygen as Oxygen Source: Synthesis of Carbamates and Ureas

Abstract

The first Rh‐catalyzed aerobic oxidative coupling reaction of isocyanides with alcohols or amines has been developed. The reaction takes place under very mild conditions, by using air as the terminal oxidant and oxygen‐atom source. It provides a simple, efficient, and general method for the construction of N‐arylcarbamates and ureas in an atom‐economic manner. Moreover, the new mechanism, involving α‐diazocarbonyl compounds as carbene precursors and a RhI/RhIII catalytic cycle with oxygen, might open up new avenues in rhodium chemistry.

Transition Metal and Inner Transition Metal Catalyzed Amide Derivatives Formation through Isocyanide Chemistry

“…135 A Rh-catalyzed oxidative coupling reaction of isocyanides and amines or alcohols was performed by Zhao and co-workers in the presence of ethyl diazoacetate as a ligand leading to ureas and N-arylcarbamates, respectively. 136 Rh(PPh 3 ) 3 Cl and ethyl diazoacetate both have a crucial role in the reaction progress and the formation of the desired products. The reaction failed using tertiary alcohols, primary amines, and aliphatic isocyanides as substrates.…”

Direct synthesis of carbamates, thiocarbamates, and ureas from Boc-protected amines: a sustainable and efficient approach

“…Acknowledging the paramount bioactivity of these compounds, 19 the development of novel and efficient synthetic methodologies is deemed crucial. Conventional synthesis pathways that rely on phosgene, 20 its derivatives, 21,22 and transition metal catalysts (including palladium, 23 nickel, 24,25 and rhodium 26,27 ) are fraught with challenges, notably the use of toxic reagents and the consequential contamination with residual heavy metals. The widespread use of tert -butoxycarbonyl (Boc) in amine protection renders Boc-protected amines readily accessible reagents, facilitating innovations in synthetic methodologies.…”

Gold-Catalyzed CN Cross-Coupling Reactions of Aryl Iodides with Alkyl Nitriles or Silver Cyanate

“…White solid, 56% (12.9 mg, petroleum ether / ethyl acetate = 10:1). ethyl [1,1'-biphenyl]-4-ylcarbamate (6i) [23] White solid, 65% (15.7 mg, petroleum ether / ethyl acetate = 10:1). propyl [1,1'-biphenyl]-4-ylcarbamate (6j) [23] White solid, 70% (17.8 mg, petroleum ether / ethyl acetate = 20:1).…”