93729-29-4Relevant academic research and scientific papers
Chemodivergent Synthesis of Oxazoles and Oxime Ethers Initiated by Selective C-N/C-O Formation of Oximes and Diazo Esters
Qi, Zhenjie,Wang, Shaozhong
supporting information, p. 8549 - 8553 (2021/10/25)
Chemodivergent reactions of oximes and diazo esters involving Rh-catalyzed [3+2] annulation and photodriven O-H insertion have been developed to generate oxazoles and oxime ethers. A range of aldehyde and ketone oximes reacted with α-diazocarbonyl compounds in a controllable manner in which functional groups, including ketone, ester, amide, ether, thiol ether, silane, alkene, allene, and alkyne groups, were well tolerated.
Effective C5-Arylation of Peptide-Integrated Oxazoles: Almazole D
Oberheide, Ansgar,Arndt, Hans-Dieter
supporting information, p. 1132 - 1136 (2020/12/22)
An efficient functionalization approach of oxazoles by using Pd-catalyzed cross-coupling reactions is reported. Oxazolone formation and subsequent sulfamoylation in situ are facilitated by employing N,N-diethylsulfamoyl imidazolium triflate. Cross-couplings provide both oxazole-arenes and oxazole-heteroarenes and were compatible with sensitive and epimerization-prone substrates, as exemplified by the total synthesis of the natural product almazole D. (Figure presented.).
NIS-TBHP promoted oxidative coupling of C–N and C–O bonds: A metal-free approach to polysubstituted oxazoles
Li, Fei,Liu, Xiaolan,Yang, Shengxiang,Yang, Yuzhu
supporting information, (2020/04/08)
A metal-free approach to polysubstituted oxazoles via the oxidative coupling of readily available benzylamines and 1,3-dicarbonyl derivatives in the presence of an external base has been developed. A variety of functional groups on both of the starting materials are tolerated using this method, affording the corresponding oxazoles in moderate to good yields. Iodination was proposed as the initiation step of the reaction and a plausible mechanism has been proposed to explain the reaction pathway.
Electrochemical Iodine-Mediated Oxidation of Enamino-Esters to 2H-Azirine-2-Carboxylates Supported by Design of Experiments
Babaoglu, Emre,Hilt, Gerhard
, p. 8879 - 8884 (2020/07/15)
An electrochemical iodine-mediated transformation of enamino-esters for the synthesis of 2H-azirine-2-carboxylates is presented. In addition, a thermic conversion of azirines to 4-carboxy-oxazoles in quantitative yield without purification was described.
A Gold-Catalyzed Acid-Assisted Regioselective Cyclization for the Synthesis of Polysubstituted Oxazoles
Wang, Qian,Hoffmann, Stephanie,Schie?l, Jasmin,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
, p. 2384 - 2388 (2020/03/19)
Polysubstituted oxazole derivatives are obtained through a regioselective gold-catalyzed reaction of α-alkynylamides and alkynoates in the presence of nitriles. The intermediary obtained gold carbenes are generated by alkyne oxidation with a pyridine N-oxide. Acidic conditions ensure that only one of the two carbonyl oxygen atoms in these intermediates selectively cyclizes to the products in excellent yields.
A Highly Efficient Heterogeneous Copper-Catalyzed Oxidative Cyclization of Benzylamines and 1,3-Dicarbonyl Compounds to Give Trisubstituted Oxazoles
Cai, Mingzhong,Tuo, Yuxin,Wei, Li,You, Shengyong
, p. 3091 - 3100 (2019/08/07)
The heterogeneous copper-catalyzed cascade oxidative cyclization between benzylamines and 1,3-dicarbonyl compounds was achieved by using the 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized copper(II) complex [MCM-41-2N-Cu(OAc) 2 ] as catalyst and t -BuOOH (TBHP) as oxidant, with iodine as additive, under mild conditions, yielding a wide variety of 2,4,5-trisubstituted oxazoles in mostly good to excellent yields. This heterogeneous copper catalyst can be facilely prepared via a simple two-step procedure from readily available and inexpensive reagents and exhibits a slightly higher activity than Cu(OAc) 2. MCM-41-2N-Cu(OAc) 2 is also easy to recover and can be recycled up to eight times with almost consistent activity. The reaction is the first example of heterogeneous copper-catalyzed intermolecular cyclization for the construction of polysubstituted oxazoles.
Electrocatalytic Tandem Synthesis of 1,3-Disubstituted Imidazo[1,5- a]quinolines via Sequential Dual Oxidative C(sp3)-H Amination in Aqueous Medium
Qian, Peng,Yan, Zicong,Zhou, Zhenghong,Hu, Kangfei,Wang, Jiawei,Li, Zhibin,Zha, Zhenggen,Wang, Zhiyong
, p. 3148 - 3157 (2019/02/14)
An NH4I-mediated tandem electrosynthesis of 1,3-disubstituted imidazo[1,5-a]quinolines was developed from readily available starting materials in aqueous medium, affording a variety of 1,3-disubstituted imidazo[1,5-a]quinolines with good to excellent yields.
Three-Component [2+2+1] Gold(I)-Catalyzed Oxidative Generation of Fully Substituted 1,3-Oxazoles Involving Internal Alkynes
Dubovtsev, Alexey Yu.,Dar'in, Dmitry V.,Kukushkin, Vadim Yu.
supporting information, p. 2926 - 2935 (2019/04/26)
Three-component [2+2+1] gold(I)-catalyzed reaction of internal alkynes (alkynyl esters or -ketones), nitriles, and 2-chloropyridine N-oxide led to a wide range of fully substituted 1,3-oxazoles (32 examples; up to 92% isolated yields). Nitrile R3/su
Pd-catalyzed desulfitative arylation for the synthesis of 2,5-diarylated oxazole-4-carboxylates using dioxygen as the terminal oxidant
Tang, Xiaodong,Yang, Kai,Zeng, Liying,Liu, Qiang,Chen, Huoji
supporting information, p. 8504 - 8507 (2017/10/27)
A desulfitative arylation of 2-aryloxazole-4-carboxylate with sodium arylsulfinates under an oxygen (O2) atmosphere to afford 2,5-diarylated oxazole-4-carboxylates is described. This transformation provides a novel approach for the utilization of sodium arylsulfinates as the aryl source and O2 as the sole oxidant.
Convenient route to trisubstituted oxazoles via a copper-catalysed tandem oxidative cyclisation by oxygen oxidation
Chen, Chengqun,Chen, Wenfu,Bao, Qianhong
, p. 7 - 10 (2015/02/05)
A novel copper-catalysed oxidative cyclisation has been developed for the synthesis of trisubstituted oxazoles, which is thought to proceed through cascade formation of C-N and C-O bonds by oxygen oxidation. The desired products can be obtained from readily available starting materials while avoiding hazardous materials. Therefore, a green synthetic method for the preparation of oxazoles has been found.
