Nucleophilic Addition of Benzimidazoles to Alkynyl Bromides/Palladium-Catalyzed Intramolecular C–H Vinylation: Synthesis of Benzo[4,5]imidazo[2,1-a]isoquinolines
摘要:
An efficient "one-pot" route for the synthesis of benzo[4,5]imidazo[2,1-a] isoquinolines has been developed via nucleophilic addition of 2-aryl benzimidazoles to alkynyl bromides and subsequent palladium-catalyzed intramolecular C-H vinylation.
Nickel catalyzed sustainable synthesis of benzazoles and purines <i>via</i> acceptorless dehydrogenative coupling and borrowing hydrogen approach
作者:Gargi Chakraborty、Rakesh Mondal、Amit Kumar Guin、Nanda D. Paul
DOI:10.1039/d1ob01154e
日期:——
benzoxazole via acceptorless dehydrogenative functionalization of alcohols. Using a bench stable, easy to prepare, and inexpensive Ni(II)-catalyst, [Ni(MeTAA)] (1a), featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)), a wide variety of polysubstituted benzimidazole, purine, benzothiazole, and benzoxazole derivatives were prepared via dehydrogenative coupling of alcohols with
Visible-Light Photoredox Catalyzed Double C–H Functionalization: Radical Cascade Cyclization of Ethers with Benzimidazole-Based Cyanamides
作者:Si Jiang、Xiao-Jing Tian、Shu-Yao Feng、Jiang-Sheng Li、Zhi-Wei Li、Cui-Hong Lu、Chao-Jun Li、Wei-Dong Liu
DOI:10.1021/acs.orglett.0c03853
日期:2021.2.5
simple ethers with cyanamides is developed at roomtemperature. This strategy involves sequential inert Csp3-H/Csp2-H functionalizations through intermolecular addition reaction of oxyalkyl radicals to N-cyano groups followed by radical cyclization of iminyl radicals in situ generated with C-2 aryl rings. This method allows for efficient synthesis of tetracyclic benzo[4,5]imidazo[1,2-c]quinazolines. Importantly
在室温下开发了一种简单的醚与氰胺的可见光光氧化还原催化的自由基级联环化反应。该策略涉及通过氧烷基自由基与N-氰基的分子间加成反应,随后通过C-2芳基环原位产生的亚氨基自由基的自由基环化,依次进行惰性C sp3- H / C sp2- H官能化。该方法可以有效合成四环苯并[4,5]咪唑并[1,2- c ]喹唑啉。重要的是,这是氰酰胺分子间-分子间自由基级联环化反应的第一个例子。
Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines from <i>ortho</i>-phenylenediamines and arylmethyl/ethyl amines
作者:Firdoos Ahmad Sofi、Rohit Sharma、Ravi Rawat、Asit K. Chakraborti、Prasad V. Bharatam
DOI:10.1039/d0nj03002c
日期:——
Visible light promoted dominosynthesis of 2-aryl benzimidazoles is reported through the reaction of ortho-phenylenediamines and arylmethyl amines underaerobicconditions. The methodology has wide substrate scope and tolerates a wide range of functional groups affording the products in high yields. The use of arylethyl amines instead of arylmethyl amines gives 2-aryl quinoxalines.
Selective C-C bonds formation, N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite
作者:Guanxin Zhu、Zheng-Chao Duan、Haiyan Zhu、Dongdong Ye、Dawei Wang
DOI:10.1016/j.cclet.2021.06.060
日期:2022.1
reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds
Cooperative iridium complex-catalyzed synthesis of quinoxalines, benzimidazoles and quinazolines in water
作者:Kaushik Chakrabarti、Milan Maji、Sabuj Kundu
DOI:10.1039/c8gc03744b
日期:——
Herein, an efficient methodology for the synthesis of a diverse class of N-heterocyclic moieties, such as quinoxalines, benzimidazoles and quinazolines, was developed in water using bio-renewable alcohols. The quinoxalines were successfully synthesized from a wide range of diamines and nitroamines with diols in air. Interestingly, benzimidazoles and quinazolines were synthesized with excellent isolated