Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine
作者:Ramesh Yella、Nilufa Khatun、Saroj Kumar Rout、Bhisma K. Patel
DOI:10.1039/c0ob01007c
日期:——
carbodiimides). The in situ generated heterocumulene on subsequent treatment with sodium azide at room temperature gave corresponding tetrazoles. The product regioselectivity for unsymmetrical 1,3-disubstituted thioureas was found to be correlated with the basicities (pKa's) of the parent amines attached to the thiourea. Aryl-sec-alkyl unsymmetrical thioureas gave thioamido guanidino products rather than the 5-aminotetrazoles
Reaction of 1,4,2-Dithiazolium Salts with Amino Compounds
作者:Katsumi Yonemoto、Isao Shibuya
DOI:10.1246/bcsj.61.4043
日期:1988.11
Systematic studies on the behavior of 1,4,2-dithiazolium cations (1) toward various amino compounds (ammonia, aliphatic and aromatic amines, hydrazine, semicarbazide, thiosemicarbazide derivatives, etc.) were performed. The reaction pathway could be classified into three types depending on possible three fission modes of the initially-formed adduct. The main products were 5-imino-1,4,2-dithiazole,
Arylthioureas with bromine or its equivalents gives no ‘Hugerschoff’ reaction product
作者:Ramesh Yella、Siva Murru、Abdur Rezzak Ali、Bhisma K. Patel
DOI:10.1039/c003892j
日期:——
The in situ generated arylâalkyl unsymmetrical thiourea obtained by the reaction of an aryl isothiocyanate with an aliphatic secondary amine on treatment with bromine or its equivalent gave exclusively a product having a thioamido guanidino moiety and not the expected Hugerschoff product 2-aminobenzothiazole. A plausible reaction mechanism has been proposed for this unprecedented transformation and the scope has been extended to various substrates.
<i>N</i>-Iodosuccinimide mediated intramolecular oxidative C(<i>sp</i><sup>2</sup>)-S bond formation for the synthesis of 2-aminobenzothiazole derivatives
作者:Atul A. Jichkar、Imran A. Opai、Nandkishor N. Karade
DOI:10.1080/17415993.2021.1989436
日期:2022.3.4
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 (sp2)-S bond construction.
A ligand free copper(II) catalyst is as effective as a ligand assisted Pd(II) catalyst towards intramolecular C–S bond formation via C–H functionalization
作者:Arghya Banerjee、Sourav Kumar Santra、Saroj Kumar Rout、Bhisma K. Patel
DOI:10.1016/j.tet.2013.08.025
日期:2013.10
Copper(I) catalysts are usually ineffective on the other hand Pd(II) catalysts are quite effective in promoting intramolecular sp2 C–H functionalization (C–S bond formation). Herein, we have developed a ligand assisted Pd(II) catalyzed C–S bond formation via C–H activation from arylthioureas leading to the formation of 2-aminobenzothiazoles for substrates bearing electron donating (EDG) groups in the