An I-2-promoted sp(3) C-H functionalization has been developed for the synthesis of 2,5-disubstituted oxazoles from easily available methyl ketones and benzylamines without any metal and peroxide catalyst. This domino oxidative cyclization process involves the cleavage of C H bond and the formation of C-N, C-O bonds. (C) 2012 Elsevier Ltd. All rights reserved.
Synthesis of Oxazoles through Copper-Mediated Aerobic Oxidative Dehydrogenative Annulation and Oxygenation of Aldehydes and Amines
作者:Zejun Xu、Chun Zhang、Ning Jiao
DOI:10.1002/anie.201206382
日期:2012.11.5
A fragment‐assembling strategy is used to form oxazoles from aryl acetaldehydes, amines, and molecular oxygen under mild conditions (see scheme). The transformation is highly efficient with the removal of six hydrogen atoms, including the cleavage of four C(sp3)H bonds.
Synthesis of 2,5-Disubstituted Oxazoles from Arylacetylenes and α-Amino Acids through an I2/Cu(NO3)2•3H2O-Assisted Domino Sequence
作者:Anxin Wu、Jungang Wang、Yan Cheng、Jiachen Xiang
DOI:10.1055/s-0037-1612087
日期:2019.4
5-disubstituted oxazoles from easily available arylacetylenes and α-amino acids in the presence of Cu(NO3)2•3H2O and iodine. This reaction process involves the I2/Cu(NO3)2•3H2O-assisted transformation of arylacetylene to α-iodo acetophenone, Kornblum oxidation to phenylglyoxal, condensation to imine, decarboxylation/annulation/oxidation reaction sequence to approach 2,5-disubstituted oxazoles.
Synthesis of 2,5-Disubstituted Oxazoles and Oxazolines Catalyzed by Ruthenium(II) Porphyrin and Simple Copper Salts
作者:Chuan Long Zhong、Bo Yang Tang、Ping Yin、Yue Chen、Ling He
DOI:10.1021/jo202663n
日期:2012.5.4
A novel and moderate synthesis of 2,5-disubstituted oxazoles and oxazolines involving ruthenium(II) porphyrin copper chloride catalyzed cyclization was developed. These reactions using readily available benzene carboxylic acids and phenylethenes or phenylacetylenes are performed under mild conditions. The reactions proceed in series, giving rise to the formation of an intermolecular C-N bond and an intramolecular C-O bond, which yield oxazole or oxazoline derivatives simultaneously.