External oxidant-free electrooxidative intramolecular S-N bond formation for one-pot synthesis for 3,5-disubstituted 1,2,4-thiadiazoles
作者:Qihao Zhong、Shouri Sheng、Junmin Chen
DOI:10.1080/10426507.2020.1768093
日期:2020.12.1
amidines or guanidines to give the corresponding imidoyl thioureas, which are further cyclized in situ via electrooxidativeintramolecular S-N bondformation to promote the final products. This protocol features a metal- and external oxidant-free approach, broad substrate scope, good functional group tolerance, excellent yields, and one-pot operation/reaction without the isolation of the intermediates
摘要 已在未分离的电解条件下开发了用于合成 5-氨基和 3,5-二氨基取代的 1,2,4-噻二唑衍生物的电化学氧化反应方案。新开发的一锅法涉及异硫氰酸酯与脒或胍反应生成相应的亚氨基硫脲,通过电氧化分子内 SN 键的形成进一步原位环化以促进最终产物。该协议具有无金属和无外部氧化剂的方法、广泛的底物范围、良好的官能团耐受性、优异的产量和一锅操作/反应,无需隔离中间体。图形概要
Sustainable and practical semi-heterogeneous photosynthesis of 5-amino-1,2,4-thiadiazoles over WS2/TEMPO
作者:Jia-Cheng Hou、Hong-Tao Ji、Yu-Han Lu、Jia-Sheng Wang、Yao-Dan Xu、Yan-Yan Zeng、Wei-Min He
DOI:10.1016/j.cclet.2024.109514
日期:2024.1
An eco-friendly and practical method for the clean preparation of 5-amino-1,2,4-thiadiazoles was developed. With WS as the semiconductor photocatalyst, both TEMPO and O (in air) as the redox catalysts, a variety of thiadiazoles were semi-heterogeneously formed in high to quantitative yields and could be easily collected by CPME extraction and rinsing. Furthermore, the catalytic system can be reusable
Directed evolution of <i>Escherichia coli</i> surface-displayed <i>Vitreoscilla</i> hemoglobin as an artificial metalloenzyme for the synthesis of 5-imino-1,2,4-thiadiazoles
original heme cofactor was used as an artificial thiourea oxidase (ATOase) to synthesize 5-imino-1,2,4-thiadiazoles. After two rounds of directed evolution using combinatorial active-site saturation test/iterative saturation mutagenesis (CAST/ISM) strategy, the evolved six-site mutation VHbSD-Co (6SM-VHbSD-Co) exhibited significant improvement in catalytic activity, with a broad substrate scope (31 examples)
An efficient one-pot synthesis of 3-substituted-5-amino-1,2,4-thiadiazoles from isothiocyanates and amidines
作者:Yong-Jin Wu、Yunhui Zhang
DOI:10.1016/j.tetlet.2008.03.030
日期:2008.4
An efficient one-pot synthesis of 3-substituted-5-amino-1,2,4-thiadiazoles from isothiocyanates and amidines is described. (c) 2008 Elsevier Ltd. All rights reserved.