Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization
摘要:
A copper(11)-catalyzed oxidative cyclization of enamides to oxazoles via vinylic C-H bond functionalization at room temperature is described. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in moderate to high yields. This reaction protocol is complementary to our previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
Convenient One-Pot Synthesis of 2,5-Disubstituted Oxazoles via a Catalytic Oxidative Dehydrogenation of F<sub>3</sub>CSO<sub>3</sub>H·SiO<sub>2</sub>-DDQ/CuCl<sub>2</sub>/LiCl
作者:Shizhen Yuan、Zhen Li、Ling Xu
DOI:10.1002/jhet.1637
日期:2013.11
A facile one‐potsynthesis of 2,5‐disubstitutedoxazoles was developed via cyclization of aldoximes and phenylacetylene then dehydrogenation oxidation. 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone was studied for the selective oxidation of oxazolines using Cu2+/Li+ as catalyst and O2 as indirect oxidant. The reaction results showed that this catalyst system can effectively catalyze the oxidation of oxazolines
Reaction of Alkynes and Azides: Not Triazoles Through Copper-Acetylides but Oxazoles Through Copper-Nitrene Intermediates
作者:Estela Haldón、Maria Besora、Israel Cano、Xacobe C. Cambeiro、Miquel A. Pericàs、Feliu Maseras、M. Carmen Nicasio、Pedro J. Pérez
DOI:10.1002/chem.201303737
日期:2014.3.17
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
Palladium-Catalyzed Cross Coupling Reactions of Oxazol-2-ylzinc Chloride Derivatives
作者:Benjamin A. Anderson、Nancy K. Harn
DOI:10.1055/s-1996-4274
日期:1996.5
Oxazol-2-ylzinc chloride derivatives were prepared by transmetallation of the corresponding oxazol-2-yllithium species. The palladium-catalyzed cross coupling reactions of the resulting organometallic reagents were investigated with aryl halides and organotriflates.
Liquid Scintillators. V. Absorption and Fluorescence Spectra of 2,5-Diaryloxazoles and Related Compounds<sup>1</sup>
作者:Donald G. Ott、F. Newton Hayes、Elizabeth Hansbury、Vernon N. Kerr
DOI:10.1021/ja01577a032
日期:1957.10
Ultraviolet absorption data and wave lengths of maximum emission and mean wave lengths of fluorescence are presented. The synthesis and evaluation as scintillator solutes of previously unreported compounds are given.
Iodine catalyzed synthesis of 2,5-substituted oxazoles from N-arylethylamides through intramolecular C(sp3)–H functionalization under metal-free conditions is described.