20852-38-4Relevant academic research and scientific papers
Copper catalyzed synthesis of benzoxazoles and benzothiazoles via tandem manner
Xu, Wan,Zeng, Meng-Tian,Liu, Sha-Sha,Li, Yue-Sheng,Dong, Zhi-Bing
, p. 4289 - 4292 (2017)
A useful protocol for the preparation of substituted 2-aminobenzoxazoles and 2-aminobenzothiazoles was presented. Under the catalysis of copper, 2-aminophenols or 2-aminothiophenols reacted with thiocarbamoyl chlorides via a tandem manner, furnishing a series of 17 benzoheterocycles smoothly with good to excellent yields (70–91%). The broad substrate scope, short reaction time, mild react conditions, easy performance and nice yields make this approach attractive, showing its practical synthetic value for the preparation of some biologically or pharmaceutically active compounds.
Practical approach for synthesis of 2-amino-benzoxazole in water
Cao, Ke,Wang, Jia-Ling,Wang, Lin-Hui
, p. 1471 - 1475 (2015)
A practical copper-catalyzed amination of benzoxazole with secondary amine in water has been developed. This reaction has proved to be effective to some cyclic amines, and the substituted group of nitrogen has a great impact on the amination reaction. A copper-catalyzed/amine-induced ring opening of the benzoxazole and recyclization/oxidation mechanism was also proposed.
Metal-free N-iodosuccinimide-catalyzed mild oxidative C-H bond amination of benzoxazoles
Wagh, Yogesh S.,Sawant, Dinesh N.,Bhanage, Bhalchandra M.
, p. 3482 - 3485 (2012)
A facile, efficient, and mild protocol for the synthesis of aminobenzoxazoles has been developed using direct oxidative C-H bond amination of benzoxazoles with secondary or primary amines. The reaction was performed using catalytic amount of N-iodosuccinimide and aqueous hydrogen peroxide as a green oxidant and in the absence of transition metals. Reaction proceeds smoothly at ambient temperature and requires shorter reaction time to furnish excellent yield of the desired products. Various cyclic, acyclic, and functionalized aliphatic amines were well tolerated under optimized reaction conditions and provided good to excellent yield of the respective aminobenzoxazoles.
Metal-Free Synthesis of 2-N,N-Dialkylaminobenzoxazoles Using Tertiary Amines as the Nitrogen Source
Pattarawarapan, Mookda,Yamano, Dolnapa,Wiriya, Nitaya,Phakhodee, Wong
, p. 6516 - 6523 (2019)
The unprecedented reaction of tertiary amines with 2(3H)-benzoxazolones has been investigated. In the presence of the Ph3P-I2 reagent system, the reaction of both acyclic and cyclic aliphatic tertiary amines led to the formation of 2-N,N-dialkylaminobenzoxazoles with the selective cleavage of an alkyl group. Especially, N-(2-iodoethyl)piperazinyl derivatives were rapidly produced in good yields when using DABCO as the nitrogen source. Only in the cases when the nucleophilicity of the substrates exceeds that of the amine, competitive self-condensation of benzoxazolones then proceeds preferentially. 31P{1H}-NMR study suggested the involvement of an aryloxyphosphonium intermediate and/or possibly 2-iodobenzoxazole which activates the C-2 position of benzoxazolones toward nucleophilic aromatic substitution.
Photoredox catalyzed dealkylative aromatic halogen substitution with tertiary amines
Dilman, Alexander D.,Frumkin, Alexander E.,Levin, Vitalij V.,Lipilin, Dmitry L.,Tyurin, Alexey Yu.
, (2021/06/18)
A reaction of aromatic halides bearing electron-withdrawing groups with tertiary amines in the presence of an iridium catalyst under blue light irradiation is described. Products of the aromatic substitution of the halide by the dialkylamino fragment are
Copper(ii) ions supported on functionalized graphene oxide: an organometallic nanocatalyst for oxidative amination of azolesviaC-H/C-N bond activation
Behzadi, Masoumeh,Mahmoodi Hashemi, Mohammad,Roknizadeh, Mostafa,Nasiri, Shahrokh,Ramazani Saadatabadi, Ahmad
supporting information, p. 3242 - 3251 (2021/02/26)
Graphene oxide (GO) was chemically modified withpara-aminobenzoic acid (PABA) to immobilize copper(ii) ions on its surface and used as a nanocatalyst for the oxidative C(sp2)-H bond amination reaction. A practical method to prepare Cu2+supported onpara-aminobenzoic acid grafted on GO was reported. The prepared Cu2+@GO/PABA was characterized by FT-IR, XRD, SEM, AFM, TEM, UV-Vis, and ICP techniques. The results showed that the morphology, distribution, and loading of copper ions could be well-adjusted by grafting of PABA on GO. Moreover, just 2 mol% of Cu2+@GO-PABA could catalyze the C-H activation reaction of benzoxazole and benzothiazole with secondary amines in >94% yields. Also, the catalyst showed very good recyclability and much less leaching of the Cu into the reaction solution. The high activity of Cu2+@GO-PABA can be ascribed to the good synergistic effects of Cu2+andpara-aminobenzoic acid grafted on graphene oxide.
Application of cuprous complex containing ortho-position carborane Schiff base ligand
-
Paragraph 0057-0062, (2020/07/21)
The invention relates to an application of a cuprous complex containing an ortho-position carborane Schiff base ligand, and a structural formula of the cuprous complex is shown in the specification, in the formula, Ar is aryl containing a benzene ring or heterocyclic aryl, and . is a boron hydrogen bond; the cuprous complex is used for catalyzing an oxidative coupling reaction of benzoxazole and amine compounds to synthesize 2-amino benzoxazole derivatives. The preparation method specifically comprises the following steps: dissolving a cuprous complex, benzoxazole and an amine compound in an organic solvent, then reacting with an oxidant at 50-80 DEG C for 6-12 hours, and separating and purifying to obtain the 2-amino benzoxazole derivative. Compared with the prior art, the cuprous complexcontaining the ortho-carborane Schiff base ligand can efficiently catalyze oxidative coupling of benzoxazole and primary amine or secondary amine to synthesize the 2-amino benzoxazole derivative; theproduct has the advantages of good selectivity, low catalyst dosage, mild reaction conditions, high reaction rate, high yield, wide substrate range and the like, and shows a wide industrial application prospect.
Zwitterionic Ring-Opened Oxyphosphonium Species from the Ph3P-I2 Mediated Reactions of Benzo[ d]oxazol-2(3 H)-ones with Secondary Amines
Pattarawarapan, Mookda,Wiriya, Nittaya,Yimklan, Saranphong,Wangngae, Sirilak,Phakhodee, Wong
, p. 6151 - 6158 (2020/05/20)
Instead of the expected substituted 2-aminobenzo[d]oxazoles, relatively stable ring-opened oxyphosphonium betaines were isolated for the first time from the Ph3P-I2-mediated reactions of benzo[d]oxazol-2(3H)-ones with acyclic seconda
HFIP Promoted Low-Temperature SNAr of Chloroheteroarenes Using Thiols and Amines
Bhujabal, Yuvraj B.,Vadagaonkar, Kamlesh S.,Gholap, Aniket,Sanghvi, Yogesh S.,Dandela, Rambabu,Kapdi, Anant R.
, p. 15343 - 15354 (2019/12/04)
A highly efficient and an unprecedented hexafluoro-2-propanol, promoting low-temperature aromatic nucleophilic substitutions of chloroheteroarenes, has been performed using thiols and (secondary) amines under base-free and metal-free conditions. The developed protocol also provides excellent regio-control for the selective functionalization of dichloroheteroarenes, while the utility of the protocol was demonstrated by the modification of a commercially available drug ceritinib.
Iodide catalyzed synthesis of 2-aminobenzoxazoles via oxidative cyclodesulfurization of phenolic thioureas with hydrogen peroxide
Yadav, Vinod K.,Srivastava, Vishnu P.,Yadav, Lal Dhar S.
, p. 252 - 255 (2017/12/26)
A convenient and efficient oxidative cyclodesulfurization of o-phenolic thioureas to 2-aminobenzoxazoles employing TBAI (tetrabutylammonium iodide)/H2O2 catalyst/reagent system is reported. The protocol utilizes and offers a number o
