@article{10272/22781,
year = {2014},
url = {https://hdl.handle.net/10272/22781},
abstract = {Well-defined copper(I) complexes of composition [Tpm*,BrCu(NCMe)]BF4 (Tpm*,Br=tris(3,5-dimethyl-4-bromo-pyrazolyl)methane) or [Tpa*Cu]PF6 (Tpa*=tris(3,5-dimethyl-pyrazolylmethyl)amine) catalyze the formation of 2,5-disubstituted oxazoles from carbonyl azides and terminal alkynes in a direct manner. This process represents a novel procedure for the synthesis of this valuable heterocycle from readily available starting materials, leading exclusively to the 2,5-isomer, attesting to a completely regioselective transformation. Experimental evidence and computational studies have allowed the proposal of a reaction mechanism based on the initial formation of a copper–acyl nitrene species, in contrast to the well-known mechanism for the copper-catalyzed alkyne and azide cycloaddition reactions (CuAAC) that is triggered by the formation of a copper–acetylide complex.},
organization = {We thank MINECO (CTQ2011–28942-CO2–01, CTQ2011–27033, CTQ2008–00947/BQU and CTQ2012–38594-C02–01) and Consolider Ingenio (2010 CSD2006–0003), Fondos Feder, DEC (2009SGR259, 2009SGR623), Junta de Andalucía (Proyectos P07-FQM-02745 and P10-FQM-06292), and the ICIQ Foundation.},
publisher = {Wiley},
title = {Reaction of Alkynes and Azides: Not Triazoles Through Copper–Acetylides but Oxazoles Through Copper–Nitrene Intermediates},
doi = {10.1002/chem.201303737},
author = {Haldón Hermoso, Estela and Besora, María and Cano Rico, Israel and Cambeiro, Xacobe C. and Pericàs, Miquel A. and Maseras, Feliu and Nicasio Jaramillo, María Carmen and Pérez Romero, Pedro José},
}