研究了在无金属中性条件下在80°C下在K 2 S 2 O 8存在下邻位取代的苯胺和芳基乙醛酸酯的环化反应,这为氮杂环的串联合成提供了平台。尽管已知芳基乙醛酸在K 2 S 2 O 8存在下会发生脱羧反应,形成一个酰基基团,并用于缺电子(杂)芳烃的Minisci酰化反应,但它们与富电子邻位的反应最近已经研究了取代苯胺形成氮杂环的方法。根据反应中使用的实验条件,已经提出了涉及酰基或芳基亚氨基羧酸反应的杂环形成机理。在存在K 2 S 2 O 8的情况下,对2-取代苯胺和芳基乙醛酸酯的环化反应机理有较深入的了解进行了广泛的机械研究。在当前的研究中,已经基于不同的可能的脱羧模式推测了各种机理途径,包括酰基,亚氨基,氨基和N,O-半缩酮的生成。基于可用的分析数据,可以支持某些建议的中间体。该协议使用一种廉价的单一试剂K 2 S 2 O 8,该试剂不仅提供了无过渡金属的条件,而且还用作关键的脱羧步骤的试剂
Accessing Polysubstituted Quinazolines via Nickel Catalyzed Acceptorless Dehydrogenative Coupling
作者:Seuli Parua、Rina Sikari、Suman Sinha、Gargi Chakraborty、Rakesh Mondal、Nanda D. Paul
DOI:10.1021/acs.joc.8b01479
日期:2018.9.21
easy to prepare nickel catalysts, containing tetraaza macrocyclic ligands (tetramethyltetraaza[14]annulene (MeTAA) or 6,15-dimethyl-8,17-diphenyltetraaza[14]annulene (MePhTAA)) are reported. A wide variety of substituted quinazolines were synthesized in moderate to high yields starting from cheap and easily available starting precursors. A few control reactions were performed to understand the mechanism
Iron-catalyzed oxidative synthesis of N-heterocycles from primary alcohols
作者:Dan Zhao、Yu-Ren Zhou、Qi Shen、Jian-Xin Li
DOI:10.1039/c3ra46363j
日期:——
An iron-catalyzed one-pot one-step oxidative system has been successfully developed in the conversion of primary alcohols into nitrogen-containing heterocycles, such as quinazolinone, quinazoline and 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide derivatives.
在伯醇转化为含氮杂环(如喹唑啉酮,喹唑啉和3,4-二氢-2 H -1,2,4-苯并噻二嗪)中,已成功开发出铁催化的一锅一步氧化系统。1,1-二氧化物衍生物。
Efficient synthesis of quinazolines by the iron-catalyzed acceptorless dehydrogenative coupling of (2-aminophenyl)methanols and benzamides
作者:Shi-Qi Zhang、Yao Cui、Bin Guo、David J. Young、Ze Xu、Hong-Xi Li
DOI:10.1016/j.tet.2020.131825
日期:2021.1
The acceptorless dehydrogenation coupling (ADC) of (2-aminophenyl)methanols with benzamides was achieved with catalytic FeCl2·4H2O in an efficient synthesis of quinazolines. This simple catalytic system is atom-economical, environmentally benign and suited to a variety of substrates.