16155-60-5Relevant academic research and scientific papers
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.
Ni-Catalyzed C?F Bond Functionalization of Unactivated Aryl Fluorides and Corresponding Coupling with Oxazoles
Yin, Youzhi,Yue, Xiaoyu,Zhong, Qi,Jiang, Hanmin,Bai, Ruopeng,Lan, Yu,Zhang, Hua
supporting information, p. 1639 - 1643 (2018/03/21)
A Ni-catalyzed C?F bond functionalization of unactivated aryl fluorides with oxazoles as coupling partners was developed. Various arylated oxazoles could be obtained in moderate to good yields in the presence of Ni(cod)2/IMes catalytic system.
Metal-free iodine(iii)-promoted synthesis of 2,5-diaryloxazoles
Yang, Xueying,Guo, Xin,Qin, Mingda,Yuan, Xinglong,Jing, Huanwang,Chen, Baohua
supporting information, p. 3104 - 3108 (2018/05/22)
A nonmetal-catalyzed oxidative cyclization to achieve 2,5-disubstituted oxazoles from inexpensive and readily available substituted chalcone, (diacetoxyiodo)benzene (PIDA) and ammonium acetate (NH4OAc) at room temperature is described. The reaction forms a variety of 2,5-diaryloxazoles in good to excellent yields with broad substrate scope under mild conditions without the requirement of ligands and additional bases.
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.
A Heterogeneous Gold(I)-Catalyzed [2 + 2 + 1] Annulation of Terminal Alkynes, Nitriles, and Oxygen Atoms Leading to 2,5-Disubstituted Oxazoles
Yang, Weisen,Zhang, Rongli,Yi, Feiyan,Cai, Mingzhong
, p. 5204 - 5211 (2017/05/24)
The first heterogeneous gold(I)-catalyzed [2 + 2 + 1] annulation of terminal alkynes, nitriles, and oxygen atoms has been achieved by using an MCM-41-immobilized phosphine-gold(I) complex as catalyst and 8-methylquinoline N-oxide as oxidant under mild conditions, yielding a variety of 2,5-disubstituted oxazoles in good to excellent yields with broad substrate scope. The new heterogeneous gold(I) catalyst can easily be recovered by simple filtration of the reaction solution and recycled for at least eight times without significant loss of activity.
A facile synthesis of 2,5-disubstituted oxazoles via a copper-catalyzed cascade reaction of alkenes with azides
Li, Jiu-Ling,Wang, Ying-Chun,Li, Wei-Ze,Wang, Heng-Shan,Mo, Dong-Liang,Pan, Ying-Ming
, p. 17772 - 17774 (2015/12/18)
A novel and efficient approach to the synthesis of 2,5-disubstituted oxazoles is developed via a 1,3-dipolar cycloaddition/ring cleavage/1,2-H migration/denitrogenation/copper-catalyzed aerobic oxidative dehydrogenative cyclization cascade. The desired products can be obtained from readily available aromatic terminal alkenes and azides employing air as the oxidant under mild conditions, and it offers an attractive alternative method for the synthesis of oxazole derivatives.
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.
Reaction of alkynes and azides: Not triazoles through copper-acetylides but oxazoles through copper-nitrene intermediates
Haldon, Estela,Besora, Maria,Cano, Israel,Cambeiro, Xacobe C.,Pericas, Miquel A.,Maseras, Feliu,Nicasio, M. Carmen,Perez, Pedro J.
, p. 3463 - 3474 (2014/04/03)
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.
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.
