100063-41-0Relevant articles and documents
Solid-phase rhodium carbenoid reactions: an N-H insertion route to a diverse series of oxazoles.
Clapham,Spanka,Janda
, p. 2173 - 2176 (2001)
[reaction: see text] The solid-phase synthesis of a series of oxazoles is described. The key step in the construction of these molecules involves the rhodium-catalyzed decomposition of polymer-bound alpha-diazo-beta-ketoesters. These reactions are performed in the presence of primary amides and yield the corresponding N-H insertion products. Subsequent cyclodehydration of these alpha-(acylamino)-beta-ketoesters provides the corresponding resin-bound 2,5-disubstituted oxazoles, which are further elaborated during cleavage from the resin.
RhII-catalyzed cycloadditions of carbomethoxy iodonium ylides
Batsila, Christina,Kostakis, George,Hadjiarapoglou, Lazaros P
, p. 5997 - 6000 (2002)
Carbomethoxy iodonium ylides, generated from methyl acetoacetate and methyl malonate, respectively, are exploited in synthesis of cyclopropanes, cyclopropenes as well as various heterocycles.
Electrochemical synthesis of 1,2,4,5-tetrasubstituted imidazoles from enamines and benzylamines
Chen, Zhiwei,Shi, Guang,Wang, Wenxing,Zhang, Shuo
supporting information, p. 6682 - 6686 (2021/08/12)
An electrochemical method for synthesizing 1,2,4,5-tetrasubstituted imidazoles was developed under undivided electrolytic conditions. This synthesis was specifically realized based on electrochemical C(sp3)-H aminationviaenamines and amines. Readily available starting materials were used, avoiding the use of both transition metals and oxidants. The practicability of the method lies in its broad substrate adaptability and in its ability to provide a simple green pathway for synthesizing GABAAreceptor analogs.
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.
The rapid synthesis of oxazolines and their heterogeneous oxidation to oxazoles under flow conditions
Gl?ckner, Steffen,Tran, Duc N.,Ingham, Richard J.,Fenner, Sabine,Wilson, Zoe E.,Battilocchio, Claudio,Ley, Steven V.
, p. 207 - 214 (2015/02/02)
A rapid flow synthesis of oxazolines and their oxidation to the corresponding oxazoles is reported. The oxazolines are prepared at room temperature in a stereospecific manner, with inversion of stereochemistry, from β-hydroxy amides using Deoxo-Fluor. The
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.
Electrochemically promoted synthesis of polysubstituted oxazoles from β-diketone derivatives and benzylamines under mild conditions
Yuan, Gaoqing,Zhu, Zechen,Gao, Xiaofang,Jiang, Huanfeng
, p. 24300 - 24303 (2014/06/24)
An efficient electrochemical synthesis of poly-substituted oxazoles from readily available β-diketone derivatives and benzylamines is described. This electrochemical procedure does not need hazardous oxidants and transition metal catalysts as well as molecular I2 additives. Compared with the traditional thermo-chemical method, the present electrochemical method is greener and more efficient. The Royal Society of Chemistry 2014.
Synthesis of new β-amidodehydroaminobutyric acid derivatives and of new tyrosine derivatives using copper catalyzed C-N and C-O coupling reactions
Pereira,Vilaca,Ferreira
, p. 335 - 344 (2013/07/05)
Several β-amidodehydroaminobutyric acid derivatives were prepared from N,C-diprotected β-bromodehydroaminobutyric acids and amides by a copper catalyzed C-N coupling reaction. The best reaction conditions include the use of a catalytic amount of CuI, N,N'-dimethylethylenediamine as ligand and K 2CO3 as base in toluene at 110 C. The stereochemistry of the products was determined using NOE difference experiments and the results obtained are in agreement with an E-stereochemistry. Thus, the stereochemistry is maintained in the case of the E-isomers of β-bromodehydroaminobutyric acid derivatives, but when the Z-isomers were used as substrates the reaction proceeds with inversion of configuration. The use of β- bromodehydrodipeptides as substrates was also tested. It was found that the reaction outcome depend on the stereochemistry of the β- bromodehydrodipeptide and on the nature of the first amino acid residue. The products isolated were the β-amidodehydrodipeptide derivatives and/or the corresponding dihydropyrazines. The same catalytic system (CuI/N,N'- dimethylethylene diamine) was used in the C-O coupling reactions between a tyrosine derivative and aryl bromides. The new O-aryltyrosine derivatives were isolated in moderate to good yields. The photophysical properties of two of these compounds were studied in four solvents of different polarity. The results show that these compounds after deprotection can be used as fluorescence markers.
Metal-free, organocatalytic cascade formation of C-N and C-O bonds through dual sp3 C-H activation: Oxidative synthesis of oxazole derivatives
Xie, Jin,Jiang, Honglai,Cheng, Yixiang,Zhu, Chengjian
supporting information; experimental part, p. 979 - 981 (2012/02/04)
An organocatalytic cascade reaction that involves the formation of C-N, C-O and CN bonds in one process via dual sp3 C-H activation has been developed. This protocol affords a facile metal-free methodology for the synthesis of oxazole derivatives in air under mild conditions.
Rhodium carbene routes to oxazoles and thiazoles. Catalyst effects in the synthesis of oxazole and thiazole carboxylates, phosphonates, and sulfones
Shi, Baolu,Blake, Alexander J.,Lewis, William,Campbell, Ian B.,Judkins, Brian D.,Moody, Christopher J.
experimental part, p. 152 - 161 (2010/04/04)
(Chemical Equation Presented) Dirhodium tetraacetate catalyzed reaction of α-diazo-β-keto-carboxylates and -phosphonates with arenecarboxamides gives 2-aryloxazole-4-carboxylates and 4-phosphonates by carbene N-H insertion and cyclodehydration. In stark contrast, dirhodium tetrakis(heptafluorobutyramide) catalysis results in a dramatic change of regioselectivity to give oxazole-5-carboxylates and 5-phosphonates. α-Diazo-β-ketosulfones behave similarly and give 5-sulfonyloxazoles upon dirhodium tetrakis-(heptafluorobutyramide) catalyzed reaction with carboxamides. The analogous reactions of thiocarboxamides give the corresponding thiazole-5-carboxylates, -phosphonates, and -sulfones. 2009 American Chemical Society.
