4225-26-7Relevant academic research and scientific papers
N-Iodosuccinimide mediated intramolecular oxidative C(sp 2)-S bond formation for the synthesis of 2-aminobenzothiazole derivatives
Jichkar, Atul A.,Opai, Imran A.,Karade, Nandkishor N.
, p. 144 - 155 (2021/10/21)
An extremely efficient synthetic method for the preparation of 2-aminobenzothiazole derivatives starting from arylthioureas by using N-iodosuccinimide has been reported. This protocol features a mild reaction conditions, a short reaction time, and metal-free oxidative conditions for C (sp 2)-S bond construction.
Ionic Reactivity of 2-Isocyanoaryl Thioethers: Access to 2-Halo and 2-Aminobenzothia/Selenazoles
Dong, Jinhuan,Hu, Junlin,Liu, Xiaoli,Sun, Shaoguang,Bao, Lan,Jia, Mengying,Xu, Xianxiu
, p. 2845 - 2852 (2022/02/23)
An ionic cascade insertion/cyclization reaction of thia-/selena-functionalized arylisocyanides has been successfully developed for the efficient and practical synthesis of 2-halobenzothiazole/benzoselenazole derivatives. This synthetic protocol, incorporating a halogen atom when forming the five-membered ring of benzothia/selenazoles, is different from the existing ones, where halogenation of the preformed benzothia/selenazole precursors happens. Additionally, a facile access to 2-aminobenzothiazoles is also achieved by the one-pot cascade reaction of 2-isocyanoaryl thioethers, iodine, and amines.
Room-Temperature Amination of Chloroheteroarenes in Water by a Recyclable Copper(II)-Phosphaadamantanium Sulfonate System
Dandela, Rambabu,Desai, Aman A.,Kapdi, Anant R.,Kori, Santosh,Maity, Dilip K.,Parmar, Udaysinh,Somvanshi, Dipesh
, p. 8900 - 8925 (2021/07/20)
Buchwald-Hartwig amination of chloroheteroarenes has been a challenging synthetic process, with very few protocols promoting this important transformation at ambient temperature. The current report discusses about an efficient copper-based catalytic system (Cu/PTABS) for the amination of chloroheteroarenes at ambient temperature in water as the sole reaction solvent, a combination that is first to be reported. A wide variety of chloroheteroarenes could be coupled efficiently with primary and secondary amines as well as selected amino acid esters under mild reaction conditions. Catalytic efficiency of the developed protocol also promotes late-stage functionalization of active pharmaceutical ingredients (APIs) such as antibiotics (floxacins) and anticancer drugs. The catalytic system also performs efficiently at a very low concentration of 0.0001 mol % (TON = 980,000) and can be recycled 12 times without any appreciable loss in activity. Theoretical calculations reveal that the π-acceptor ability of the ligand PTABS is the main reason for the appreciably high reactivity of the catalytic system. Preliminary characterization of the catalytic species in the reaction was carried out using UV-VIS and ESR spectroscopy, providing evidence for the Cu(II) oxidation state.
Morpholine derivative oxidation ring-opening method and product thereof
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Paragraph 0039; 0052-0054, (2021/07/08)
The invention relates to a morpholine derivative oxidation ring-opening method and a product thereof, and belongs to the technical field of compound preparation. The method for promoting oxidative cracking of C (sp3)-C (sp3) bonds of a morpholine derivative by visible light has been successfully developed under the inspiration of the design concept of visible light induced C (sp3)-C (sp3) bond cracking. According to the morpholine derivative oxidation ring-opening method, C (sp3)-C (sp3) bonds without ring stress are cracked by using visible light as an energy source and O2 as a final oxidizing agent, use of transition metal, high temperature, high pressure and chemical equivalent dangerous oxidizing agents is avoided, good functional group tolerance is established, 30 substrates are obtained, the yield is as high as 83%, and a supplementary scheme is provided for realizing oxidative cracking of the morpholine derivative under a mild condition.
Visible-Light-Mediated Aerobic Oxidative C(sp3)?C(sp3) Bond Cleavage of Morpholine Derivatives Using 4CzIPN as a Photocatalyst
Dong, Chun-Lin,Huang, Lan-Qian,Guan, Zhi,Huang, Chu-Sheng,He, Yan-Hong
supporting information, p. 3803 - 3811 (2021/06/28)
Herein, a metal-free strategy for the aerobic oxidative cleavage of the inert C(sp3)?C(sp3) bond was developed. Deconstruction of morpholine derivatives was conducted using visible light as an energy source and O2 as an oxidant under mild conditions. This procedure demonstrated suitable selectivity and functional group tolerance. Moreover, a possible mechanism involving a radical process was proposed based on a series of mechanism exploration and control experiments. (Figure presented.).
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.
A Mild Synthesis of 2-Substituted Benzothiazoles via Nickel-Catalyzed Intramolecular Oxidative C-H Functionalization
Gao, Ming-Yuan,Li, Jing-Hang,Zhang, Shi-Bo,Chen, Li-Jun,Li, Yue-Sheng,Dong, Zhi-Bing
, p. 493 - 500 (2020/02/04)
A highly efficient synthetic method for the preparation of 2-aminobenzothiazoles starting from arylthioureas has been reported. By using a nickel catalyst, arylthioureas undergo intramolecular oxidative C-H bond functionalization, giving the desired 2-aminobenzothiazoles in good to excellent yields. This protocol features an inexpensive catalyst, low catalyst loading, mild reaction conditions, a short reaction time, and good to excellent yields, and it can be scaled up easily to a gram scale with almost no yields decreasing.
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.
Dioxygen-triggered oxidative cleavage of the C-S bond towards C-N bond formation
Lv, Zongchao,Wang, Huamin,Quan, Zhicong,Gao, Yuan,Lei, Aiwen
supporting information, p. 12332 - 12335 (2019/10/19)
Research on the cleavage of C-C bonds has been well developed. By comparison with this, the activation of C-S bonds remains challenging. Herein, dioxygen-triggered oxidative cleavage of C-S bonds has been achieved, delivering a series of N-containing heterocyclic compounds that are frequently found in pesticides and pharmaceuticals. Additionally, the potential utility of this protocol was further demonstrated by a gram-scale experiment. Mechanistically, dioxygen plays a key role in the cleavage of C-S bonds towards C-N bond formation.
Solid Supported Nano Structured Cu-Catalyst for Solvent/Ligand Free C2 Amination of Azoles
Dutta, Pratip Kumar,Sen, Subhabrata,Saha, Debasree,Dhar, Basabbijayi
supporting information, p. 657 - 665 (2018/02/14)
Ligand- and solvent-free catalytic conditions that harness a nanostructured–CuI catalyst encapsulated in TiO2 has been reported for C2-amination of azoles (benzothiazole, benzoxazole and thiazole). The reaction is highly regioselective. The catalyst is robust, inexpensive and can be recycled up to four times. This strategy was further used for the synthesis of a small molecule with anti-HIV and anti-tumor properties.
