A copper-catalyzed three-component coupling reaction of azoles, Se powder, and aryliodide is described for the first time. This transformation provides a straightforward and facile pathway to synthesis 2-arylselanyl-azoles via a copper-catalyzed double C–Se bonds formation process. This reaction is attractive and practical since the cheap copper catalyst is employed and it does not require ligands
Inexpensive copper catalysts enabled direct C–H chalcogenations at ambient temperature by means of photo-induced catalysis. The expedient copper catalysis set the stage for C–S and C–Se bond formation from readily accessible non-volatile elemental chalcogens. The photo-assisted copper catalysis manifold proved suitable for a wide range of substrates with good functional group tolerance and exhibited
Copper Oxide Nanoparticle-Catalyzed Chalcogenation of the Carbon-Hydrogen Bond in Thiazoles: Synthesis of 2-(Organochalcogen)thiazoles
作者:Alisson R. Rosario、Kamila K. Casola、Carla E. S. Oliveira、Gilson Zeni
DOI:10.1002/adsc.201300497
日期:2013.10.11
AbstractWe present (homepage: www.ufsm.br) herein the application of copper nanoparticles/diorganyl dichalcogenides to promote the synthesis of 2‐(organochalcogen)thiazoles via direct carbon‐hydrogen bond activation in thiazoles. A systematic study of the catalytic system revealed that the presence and amount of base played an essential role in this reaction. The results revealed that electron‐donating and electron‐withdrawing substituents, in the aromatic ring bonded to the chalcogen atom of diorganyl dichalcogenides, required one equiv. of base, while when neutral substituents were present two equiv. of base were needed to deliver the products in similar yields.magnified image