A novel method for the stereospecificsynthesis of 1,5-disubstituted tetrazoles from ketoximes via the Beckmann rearrangement was developed using diphenyl phosphorazidate (DPPA) as both the oxime activator and azide source. Various ketoximes were transformed into the corresponding 1,5-disubstituted tetrazoles with exclusive trans-group migration and no E-Z isomerization of the ketoxime. This method
Copper-Catalyzed Oxidative Transformation of Secondary Alcohols to 1,5-Disubstituted Tetrazoles
作者:Balaji V. Rokade、Karthik Gadde、Kandikere Ramaiah Prabhu
DOI:10.1002/adsc.201300863
日期:2014.3.24
A mild and convenient oxidativetransformation of secondaryalcohols to 1,5‐disubstituted tetrazoles is uncovered by employing trimethylsilyl azide (TMSN3) as a nitrogen source in the presence of a catalytic amount of copper(II) perchlorate hexahydrate [Cu(ClO4)2.6 H2O] (5 mol%) and 2,3‐dichloro‐5,6‐dicyano‐para‐benzoquinone (DDQ) (1.2 equiv.) as an oxidant. This reaction is performed under ambient
在催化量的高氯酸铜(II)六水合物[Cu(ClO 4)]存在下,通过使用三甲基叠氮化硅(TMSN 3)作为氮源,发现了中等程度的醇向1,5-二取代的四唑进行温和且方便的氧化转化。2 。6 H 2 O](5 mol%)和2,3-二氯-5,6-二氰基对苯醌(DDQ)(1.2当量)作为氧化剂。该反应在环境条件下进行,并通过CC键裂解进行。
Dehydrative Beckmann rearrangement and the following cascade reactions
作者:Yongjiao Wei、Yinghui Liu、Lan-Gui Xie
DOI:10.1016/j.cclet.2021.10.020
日期:2022.5
The Beckmannrearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmannrearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and
Site-selective arene C-H amination via photoredox catalysis
作者:Nathan A. Romero、Kaila A. Margrey、Nicholas E. Tay、David A. Nicewicz
DOI:10.1126/science.aac9895
日期:2015.9.18
cross-coupling chemistry has developed into one of the most reliable approaches to assemble complex aromatic compounds from preoxidized starting materials. More recently, transitionmetal–catalyzed carbon-hydrogen activation has circumvented the need for preoxidized starting materials, but this approach is limited by a lack of practical aminationprotocols. Here, we present a blueprint for aromatic carbon-hydrogen
为芳基 CN 键合开辟道路 药物化学家喜欢将 N 键添加到芳环的 C 原子上以制造生物活性化合物。通过利用可见光中的能量,Romero 等人。建立这些联系并将 CH 转化为 CN 键。他们使用一种吸收蓝色的吖啶离子来激活一个环 C 以供传入的 N 伙伴使用。然后,硝酰基自由基助催化剂 (TEMPO) 对 H 原子向 O 的转移进行了编排。该反应适用于广泛的底物,包括作为 N 源的铵。科学,这个问题 p。1326 两种催化剂利用可见光和氧气形成药物研究中感兴趣的碳氮键基序。在过去的几十年里,有机金属交叉偶联化学已发展成为从预氧化起始材料组装复杂芳香族化合物的最可靠方法之一。最近,过渡金属催化的碳氢活化避免了对预氧化起始材料的需求,但这种方法因缺乏实用的胺化方案而受到限制。在这里,我们提出了通过光氧化还原催化进行芳香碳氢功能化的蓝图,并描述了该策略在芳烃胺化中的应用。一种基于有机光氧化还原的催
Construction of 5-Aminotetrazoles via in Situ Generation of Carbodiimidium Ions from Ketones Promoted by TMSN<sub>3</sub>/TfOH
5-aminotetrazoles has been developed by employing simple ketones as substrates. This methodology involved the N2-extrusion/aryl migration of azido complexes as the key step for the in situ generation of carbodiimidium ion, which could further react with hydrazoic acid and cyclize intramolecularly to provide 5-aminotetrazoles in good to excellent yields. In addition, the regioselectivity of the reaction was studied