24285-73-2Relevant academic research and scientific papers
Photoinduced Heterogeneous C?H Arylation by a Reusable Hybrid Copper Catalyst
Choi, Isaac,Müller, Valentin,Lole, Gaurav,K?hler, Robert,Karius, Volker,Vi?l, Wolfgang,Jooss, Christian,Ackermann, Lutz
supporting information, p. 3509 - 3514 (2020/03/03)
Heterogeneous copper catalysis enabled photoinduced C?H arylations under exceedingly mild conditions at room temperature. The versatile hybrid copper catalyst provided step-economical access to arylated heteroarenes, terpenes and alkaloid natural products with various aryl halides. The hybrid copper catalyst could be reused without significant loss of catalytic efficacy. Detailed studies in terms of TEM, HRTEM and XPS analysis of the hybrid copper catalyst, among others, supported its outstanding stability and reusability.
CO2/Photoredox-Cocatalyzed Tandem Oxidative Cyclization of α-Bromo Ketones and Amines to Construct Substituted Oxazoles
Zhang, Xiaowei,He, Yonghui,Li, Jing,Wang, Rui,Gu, Lijun,Li, Ganpeng
, p. 8225 - 8231 (2019/06/17)
CO2/photoredox-cocatalyzed tandem oxidative cyclization of α-bromo ketones and amines for the preparation of substituted oxazoles has been achieved. The avoidance of using both transition-metal catalysts and peroxides makes this method more sustainable and renewable.
Divergent Conversion of N-Acyl-isoxazol-5(2 H)-ones to Oxazoles and 1,3-Oxazin-6-ones Using Photoredox Catalysis
Mei, Mingjing,Anand, Devireddy,Zhou, Lei
supporting information, p. 3548 - 3553 (2019/05/24)
The fragmentation of N-acyl-isoxazol-5-ones using visible light photoredox catalysis has been disclosed. The catalyst-controlled divergent mechanisms, namely the oxidative and reductive quenching catalytic cycle, are utilized. Various oxazoles and 1,3-oxazin-6-ones are selectively obtained from the same isoxazol-5-one skeleton under mild conditions.
Synthesis of 2,5-disubstituted oxazoles: Via cobalt(III)-catalyzed cross-coupling of N -pivaloyloxyamides and alkynes
Yu, Xiaolong,Chen, Kehao,Wang, Qi,Zhang, Wenjing,Zhu, Jin
supporting information, p. 1197 - 1200 (2018/02/09)
An efficient synthesis of 2,5-disubstituted oxazoles via Co(iii) catalysis is described herein. The synthesis is achieved under mild conditions through [3+2] cycloaddition of N-pivaloyloxyamides and alkynes. The reaction operates through an internal oxidation pathway and features a very broad substrate scope. The one-step synthesis of natural products such as texamine and balsoxin has been demonstrated via this protocol.
Photoinduced Copper-Catalyzed C-H Arylation at Room Temperature
Yang, Fanzhi,Koeller, Julian,Ackermann, Lutz
supporting information, p. 4759 - 4762 (2016/04/19)
Room-temperature azole C-H arylations were accomplished with inexpensive copper(I) compounds by means of photoinduced catalysis. The expedient copper catalysis set the stage for site-selective C-H arylations of non-aromatic oxazolines under mild reaction conditions, and provides step-economical access to the alkaloid natural products balsoxin and texamine. Copper light: Room-temperature C-H arylations of heteroarenes were accomplished with inexpensive copper compounds by photoinduced catalysis. The expedient copper catalysis leads to site-selective C-H arylations of non-aromatic oxazolines under mild reaction conditions, and provides step-economical access to the alkaloid natural products balsoxin and texamine.
N -Bromosuccinimide as a Brominating Agent for the Transformation of N -H (or N -Benzyl) Ketoaziridines into Oxazoles
Samimi, Heshmat A.,Dadvar, Farkhondeh
, p. 1899 - 1904 (2015/06/30)
A novel procedure for the direct synthesis of 2,5-diaryloxazoles starting from N-H ketoaziridines is described. The method proceeds via the in situ formation of N-bromoketoaziridines in the presence of N-bromosuccinimide followed by the generation of intermediate azomethine ylides. A plausible mechanism for this transformation is proposed.
Iodine catalysed intramolecular C(sp3)-H functionalization: synthesis of 2,5-disubstituted oxazoles from N-arylethylamides
Samanta, Supravat,Donthiri, Ramachandra Reddy,Dinda, Milan,Adimurthy, Subbarayappa
, p. 66718 - 66722 (2015/08/24)
Iodine catalyzed synthesis of 2,5-disubstituted oxazoles from N-arylethylamides through intramolecular C(sp3)-H functionalization under metal-free conditions is described. The method is tolerable to a wide range of substrates having a variety of functional groups with moderate to good yields of the products.
Copper-catalyzed oxidative cyclization of chalcone and benzylic amine leading to 2,5-diaryl oxazoles via carbon-carbon double bond cleavage
Liu, Dongfang,Yu, Jintao,Cheng, Jiang
supporting information, p. 1149 - 1153 (2014/02/14)
A copper-catalyzed oxidative cyclization of chalcone with benzylic amine is achieved, providing 2,5-diaryl oxazoles in moderate to good yields. The procedure employs O2 as a clean oxidant and involves an oxidative cleavage of the CC bond as the key step.
Convenient one-pot synthesis of 2,5-disubstituted oxazoles via a catalytic oxidative dehydrogenation of F3CSO3H·SiO 2-DDQ/CuCl2/LiCl
Yuan, Shizhen,Li, Zhen,Xu, Ling
, p. 1405 - 1409 (2014/01/06)
A facile one-pot synthesis of 2,5-disubstituted oxazoles 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 to the corresponding oxazoles. Thus, a variety of polysubstituted oxazoles was easily synthesized in high yields by catalytic oxidation of 2,3-dichloro-5,6-dicyano-1, 4-benzoquinone/CuCl2/LiCl/O2.
I2/TBHP-mediated domino process: A convenient route to 1,3-oxazole derivatives
Feng, Cheng-Tao,Zhao, Ming,Ma, Shi-Tang,Qin, Xia
, p. 3835 - 3841 (2013/10/22)
A practical and simple synthesis of 2,5-disubstituted oxazoles was developed via a TBHP (tert-butyl hydroperoxide)/I2-mediated domino strategy. The reaction proceeds in series, giving rise to the formation of an intermolecular C-N bond and an intramolecular C-O bond, which yield oxazole derivatives simultaneously. The reaction gave the desired products from readily available substrates under mild conditions.
