A Study of Competitive Coordination of Benzochalcogenazole Ligands by Heteronuclear NMR Spectroscopy
摘要:
Complexes of 2-methyl(phenyl)benzo-1,3-tellurazole and 2-methyl(phenyl)benzo-1,3-selenazole with tungsten pentacarbonyl and boron trifluoride were studied by heteronuclear NMR spectroscopy (H-1, C-13, Se-77, and Te-125). The coordination mode of the ambident ligand can be determined from the coordination shifts of the Te-125 and Se-77 NMR signals: upfield at coordination via Te and Se atoms and downfield at N coordination.
1,3-benzoselenazoles having a heteroatom substituent such as NRR‘, OR, and SR groups at the 2-position was developed by the copper(I)-catalyzed reaction of 2-bromophenyl (1) or 2-iodophenyl (2) isocyanides with selenium and heteroatom nucleophiles. In addition, the synthesis of 2-amino-1,3-benzotellurazoles is also described.
α-Keto Acids as Acylating Agents in the Synthesis of 2-Substituted Benzothiazoles and Benzoselenazoles
作者:David B. Lima、Filipe Penteado、Marcelo M. Vieira、Diego Alves、Gelson Perin、Claudio Santi、Eder J. Lenardão
DOI:10.1002/ejoc.201700648
日期:2017.7.17
Herein is reported the first decarboxylative oxidation of α-keto acids promoted by sodium metabisulfite (Na2S2O5) to obtain 2-substituted benzothiazoles and benzoselenazoles. Diaryl disulfides and diselenides were used as chalcogen sources and the desired products were obtained in moderate to excellent yields. This protocol does not require inert atmosphere, transition metals or drastic reaction conditions
本文报道了由焦亚硫酸钠 (Na2S2O5) 促进的 α-酮酸的第一次脱羧氧化,以获得 2-取代的苯并噻唑和苯并硒唑。二芳基二硫化物和二硒化物用作硫属元素源,并且以中等至极好的收率获得了所需产物。该协议不需要惰性气氛、过渡金属或剧烈的反应条件,并且 CO2 作为环境良性副产品释放。Na2S2O5 的存在对于保证反应完成和产物的最大产率是必不可少的。
Novel benzyne additions to the 1,2,5-thiadiazole and 1,2,5-selenadiazole ring systems
作者:Martin R. Bryce、Peter Hanson、John M. Vernon
DOI:10.1039/c39820000299
日期:——
Novel Modes of benzyneaddition to 3,4-dimethyl-1,2,5-thiadiazole and 3,4-dimethyl-1,2,5-selenadiazole afford methyl derivatives of three heterocyclic systems: quinoxaline, 1,2-benzisothiazole, and 1,3-benzoselenazole respectively.
Synthesis of 2-Substituted 1,3-Benzoselenazoles from Carboxylic Acids Promoted by Tributylphosphine
作者:Cátia Schwartz Radatz、Daniel S. Rampon、Renata A. Balaguez、Diego Alves、Paulo Henrique Schneider
DOI:10.1002/ejoc.201402808
日期:2014.11
the synthesis of 2-substituted1,3-benzoselenazoles by the reaction of bis(2-aminophenyl)diselenide with a wide range of carboxylicacids, promoted by tributylphosphine. This efficient reaction furnishes 2-aryl-1,3-benzoselenazoles in good yields and tolerates a variety of substituents at the aryl moiety of carboxylicacids. For the first time, 2-alkyl-1,3-benzoselenazoles could be obtained from aliphatic
Copper-Catalyzed Three-Component One-Pot Synthesis of Substituted 2-Aryl-1,3-benzoselenazoles
作者:Ling Huang、Xingshu Li、Tao Su、Shishun Xie、Bifu Li、Jun Yan
DOI:10.1055/s-0034-1378934
日期:——
A simple copper-catalyzed, one-potsynthesis of 2-aryl-1,3-benzoselenazole derivatives was developed using inexpensive, readily available 2-iodoanilines, selenium powder, and aromatic aldehydes as the starting materials. The mild reaction conditions and simple procedure without ligands and other additives make this methodology an alternative for preparing these potential selenium-containing compounds