17229-76-4Relevant academic research and scientific papers
A biomass-derived N-doped porous carbon catalyst for the aerobic dehydrogenation of nitrogen heterocycles
Cui, Fu-Jun,Guo, Fu-Hu,Liu, Jing-Jiang,Liu, Xiao-Yu,Quan, Zheng-Jun,Ullah, Arif,Wang, Xi-Cun,Zhu, Ji-Hua
supporting information, p. 1791 - 1799 (2022/01/31)
N-doped porous carbon (NC) was synthesized from sugar cane bagasse, which is a sustainable and widely available biomass waste. The preferred NC sample had a well-developed porous structure, a graphene-like surface morphology and different N species. More
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
supporting information, p. 4843 - 4848 (2021/06/28)
A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
Photocatalytic green synthesis of benzazoles from alcohol oxidation/toluene sp3C-H activation over metal-free BCN: effect of crystallinity and N-B pair exposure
Cheng, Hongmei,Gao, Xue,Jiang, Heyan,Sun, Bin,Zang, Cuicui
, p. 7955 - 7962 (2021/12/27)
Porous borocarbonitride (P-BCN), with the characteristics of enhanced crystallinity and improved N-B pair exposure, was prepared with a simple KCl-assisted molten salt strategy. Efficient heterogeneous photocatalytic tandem synthesis of benzazoles from alcohol oxidation/toluene sp3C-H activation was achieved firstly over the metal-free P-BCN using visible light and the green oxidant O2, with only water as a by-product. Variouso-thio/hydroxy/aminoanilines and alcohols or toluenes could be converted to the corresponding 2-substituted benzothiazoles, benzoxazoles and benzimidazoles with good to excellent photocatalytic performance. The improved photocatalytic performance in comparison to bulk BCN should be due to the crystallinity-enhancement-induced improvement in charge separation and transmission. The increased N-B pair exposure promoted superoxide radical generation due to the electron-enriched N atoms, as well as improved oxidation ability due to the valence band constructed by the B 2p orbital. This work presents a green and efficient synthetic strategy towards benzazoles and other fine chemicalsviametal-free heterogeneous photocatalysis.
Visible-light-mediated organoboron-catalysed metal-free dehydrogenation of N-heterocycles using molecular oxygen
Wei, Lanfeng,Wei, Yu,Xu, Liang,Zhang, Jinli
supporting information, p. 4446 - 4450 (2021/06/30)
The surge of photocatalytic transformation not only provides unprecedented synthetic methods, but also triggers the enthusiasm for more sustainable photocatalysts. On the other hand, oxygen is an ideal oxidant in terms of atom economy and environmental friendliness. However, the poor reactivity of oxygen at the ground state makes its utilization challenging. Herein, a visible-light-induced oxidative dehydrogenative process is disclosed, which uses an organoboron compound as the photocatalyst and molecular oxygen as the sole oxidant.Viathis approach, an array of N-heterocycles have been accessed under metal-free mild conditions, in good to excellent yields.
Method for preparing N - heterocyclic ring through visible light mediated dehydrogenation
-
Paragraph 0142-0147, (2021/10/02)
The invention discloses a method for preparing N - heterocyclic rings through visible light mediated dehydrogenation, and the reaction can be carried out under the conditions of room temperature and visible light without heating. The novel tetra-coordination N-N - diaryl chelating borate compound serves as a photocatalyst, so that the use of a noble metal photocatalyst is avoided, precious metal residue in the reaction product can be reduced as much as possible, and the method is more suitable for synthesizing bioactive molecules.
Iodine-promoted ring-opening methylation of benzothiazoles with dimethyl sulfite
Guo, Ying-Qiong,Chen, Fan,Deng, Chen-Liang,Zhang, Xing-Guo
supporting information, p. 1923 - 1926 (2021/03/02)
A halogen-bond promoted ring-opening methylation of benzothiazoles has been developed using dimethyl sulphite as a methylating reagent in the presence of a base. This approach represents a simple and efficient synthesis ofN-methyl-N-(o-methylthio)phenyl amides, and features direct construction of both N-Me and S-Me bonds in a one-pot reaction through the decomposition of easily prepared benzothiazoles.
Photocatalyst- And Transition-Metal-Free Visible-Light-Promoted Intramolecular C(sp2)-S Formation
Wang, Hao,Wu, Qi,Zhang, Jian-Dong,Li, Hai-Yan,Li, Hong-Xi
, p. 2078 - 2083 (2021/04/05)
A photocatalyst- and transition-metal-free visible-light-induced cyclization of ortho-halothiobenzanilides has been developed. Upon irradiation with visible light, substrates undergo dehalogenative cyclization to 2-aryl benzothiazoles with high efficiency and selectivity. This photocyclization exhibits a high tolerance to various functional groups, is applicable for the synthesis of 2-alkyl benzothiazoles, and is easy to set up for gram-scale reaction.
Method for preparing alkyl benzothiazole derivative under visible light
-
Paragraph 0027-0029, (2021/06/22)
The invention discloses a method for preparing an alkyl benzothiazole derivative under visible light, which specifically comprises the following steps: under the protection of inert gas, adding N-(2-bromophenyl) alkyl thioamide and inorganic base into a reaction container provided with a stirring device, then adding dimethyl sulfoxide, stirring and reacting for 24 hours at room temperature under the irradiation of visible light, and obtaining the alkyl benzothiazole derivative. Under the condition of not adding any photosensitizer or transition metal catalyst, sodium phosphate is used as alkali, and under the irradiation of a 45W household compact fluorescent lamp, a series of intramolecular cross-coupling reactions of N-(2-bromophenyl) alkyl thioamide are realized. In addition, the alkylbenzothiazole derivative can be obtained with high yield. The whole process is green, efficient and easy to operate, and the method is a good method for synthesizing the alkylbenzothiazole derivative.
Insertion Reaction of 2-Halo- N -allylanilines with K 2S Involving Trisulfur Radical Anion: Synthesis of Benzothiazole Derivatives under Transition-Metal-Free Conditions
Liu, Xin-Yu,Zhao, Yan-Wei,Jiang, Tian,Rao, Weidong,Wang, Shun-Yi
, p. 971 - 977 (2020/12/28)
A synthesis of benzothiazole derivatives through the reaction of 2-halo- N -allylanilines with K 2S in DMF is developed. The trisulfur radical anion S 3· -, which is generated in situ from K 2S in DMF, initiates
Photocatalytic Oxidative C-H Thiolation: Synthesis of Benzothiazoles and Sulfenylated Indoles
Aceves, Ernesto Millan,Albright, Samuel T.,Cedano, Mario R.,Dinh, Andrew N.,Gustafson, Jeffrey L.,Nguyen, Ashley D.,Smith, Diane K.
supporting information, p. 1648 - 1655 (2019/08/26)
We report studies on the photocatalytic formation of C-S bonds to form benzothiazoles via an intramolecular cyclization and sulfenylated indoles via an intermolecular reaction. Cyclic voltammetry (CV) and density functional theory studies suggest that benzothiazole formation proceeds via a mechanism that involves an electrophilic sulfur radical, while the indole sulfenylation likely proceeds via a nucleophilic sulfur radical adding into a radical cationic indole. These conditions were successfully extended to several thiobenzamides and indole substrates.
