报道了 Co 和 Mn 催化的烯烃加氢肼和加氢叠氮化反应的发现、研究和实施。这些反应等效于 CC 双键与受保护的肼或偶氮酸的直接加氢胺化,但基于不同的概念,其中 H 和 N 原子来自两种不同的试剂,硅烷和氧化性氮源(偶氮二羧酸或磺酰叠氮化物) )。使用偶氮二羧酸二叔丁酯的加氢肼反应具有使用方便、官能团耐受性大、适用范围广的特点,包括单、二、三和四取代烯烃。氢叠氮化反应发展的关键是使用磺酰叠氮化物作为氮源和叔丁基过氧化氢的活化作用。发现该反应对于单、二和三取代烯烃的官能化是有效的,并且只有少数官能团是不能容忍的。获得的烷基叠氮化物是通用中间体,可以在不分离叠氮化物的情况下转化为游离胺或三唑。初步的机理研究表明,烯烃的氢化钴是限速的,然后是胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。
General Reactivity of 2-Lithiobenzothiazole to Various Electrophiles and the Use as a Formyl Anion Equivalent in the Synthesis of α-Hydroxy Carbonyl Compounds
demonstrated by its reaction with phenacyl halides and 5-chloro-2-pentanone leading to the formation of benzothiazolyl-substituted small-ring ethers. In order to demonstrate the value of 2-lithiobenzothiazole as a masked formyl anion, 2-(α-hydroxyalkyl)benzothiazoles were transformed into α-hydroxy carbonyl compounds in three reaction steps without masking the α-hydroxygroups. Quaternization of various
Visible Light‐Induced Decarboxylative Alkylation of Heterocyclic Aromatics with Carboxylic Acids via Anthocyanin as a Photocatalyst
作者:Rui Guo、Minghui Zuo、Qinye Tian、Chuanfu Hou、Shouneng Sun、Weihao Guo、Hongfeng Wu、Wenyi Chu、Zhizhong Sun
DOI:10.1002/asia.202000277
日期:2020.7
A visiblelight‐induced decarboxylative alkylation of heterocyclic aromatics with aliphatic carboxylicacids was developed by using anthocyanins as a photocatalyst under mild conditions. A series of alkylated heterocyclic compounds were obtained in moderate to good yields by using the metal‐free decarboxylative coupling reaction under blue light. This strategy uses cheap and readily available carboxylic
Rearrangement in the Synthesis of Annulated Lactams Starting from Benzothiazines
作者:Timo Stalling、Wolfgang Saak、Jürgen Martens
DOI:10.1002/ejoc.201300768
日期:2013.10
the one hand, different types of unknown lactam systems with and without a rearrangement under ring contraction of the benzothiazine substructure were selectively obtained. In this investigation, annulated lactams without ring contraction were formed by oxidation of the sulfide group to a sulfone group in the benzothiazine skeleton. On the other hand, benzothiazoles, which are oxidation products, were
基于亚胺 1,4-苯并噻嗪的甲氧基酰胺的转化根据取代模式产生了三种不同的产品。一方面,选择性地获得了不同类型的未知内酰胺体系,在苯并噻嗪亚结构的环收缩下有和没有重排。在这项研究中,没有环收缩的环状内酰胺是通过将硫化物基团氧化成苯并噻嗪骨架中的砜基团而形成的。另一方面,分离出氧化产物苯并噻唑。所有类型内酰胺的结构均通过 X 射线衍射验证。
Visible light-induced hydroxyalkylation of 2H-benzothiazoles with alcohols via selectfluor oxidation
Abstract A visible-light induced metal-free approach was described for the hydroxyalkylation of 2H-benzothiazoles with alcohols by using selectfluor as the oxidant. A variety of 2H-benzothiazoles and alcohols could be tolerated, providing a mild and simple method for the synthesis of C2-hydroxyalkylated 2H-benzothiazoles in moderate to good yields. Besides, ethers were also compatible in this reaction
Direct C2-Alkylation of Azoles with Alcohols and Ethers through Dehydrogenative Cross-Coupling under Metal-Free Conditions
作者:Tao He、Lin Yu、Lei Zhang、Lei Wang、Min Wang
DOI:10.1021/ol201779n
日期:2011.10.7
metal-free novel, simple, and highly efficient method for the direct C2-alkylation of azoles with alcohols and ethers has been developed on the basis of an oxidative C–H activation process. The dehydrogenative C–C cross-coupling reactions of α-position sp3 C–H in alcohols and ethers with the 2-position sp2 C–H in azoles proceeded smoothly in the presence of tert-butyl hydroperoxide (TBHP) under neat reaction