对Co-和CoFe 2 O 4 -NP在C–N和C–O键形成中的催化活性的比较研究:由邻卤代苯胺合成苯并咪唑和苯并恶唑†
摘要:
合成了钴铁氧体(CoFe 2 O 4 -NPs)和纯钴(Co-NPs)的纳米粒子,表征后,研究和比较了它们对脱卤分子内C-O和C-N键形成反应的催化活性。这些廉价而高效的催化剂能够创造出在绿色介质中合成苯并咪唑和苯并恶唑的新方法,且无配体且反应条件温和。在优化的反应条件下,所有反应均产生中等至极好的收率。然而,使用Co-NP作为催化剂的反应在相对较短的反应时间内完成。此外,分析表明,两个催化体系的可重复使用性大致相当。
Parallel Synthesis of a Library of Benzoxazoles and Benzothiazoles Using Ligand-Accelerated Copper-Catalyzed Cyclizations of <i>ortho</i>-Halobenzanilides
作者:Ghotas Evindar、Robert A. Batey
DOI:10.1021/jo051927q
日期:2006.3.1
A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C−O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination
Synthesis of Benz-Fused Azoles via C-Heteroatom Coupling Reactions Catalyzed by Cu(I) in the Presence of Glycosyltriazole Ligands
作者:Nidhi Mishra、Anoop S. Singh、Anand K. Agrahari、Sumit K. Singh、Mala Singh、Vinod K. Tiwari
DOI:10.1021/acscombsci.9b00004
日期:2019.5.13
and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles
The irdium-catalyzed intramolecular arylcarbon-hetero cross-coupling reactions with o-haloarylamides or o-haloarylamidine have been effectively achieved using KOAc and just 1 mol% catalyst. The [Ir(cod)Cl]2 was proved to be more potential for smoothly assembling functional structures benzimidazoles, benzoxazoles and benzothiazoles, which was superior to Cu- and Pd-catalyzed systems. Simultaneously
Oxazolidin-2-one-Promoted CuI-Catalyzed Amidation of Aryl Halides and Cyclization of <i>o</i>-Halobenzanilides
作者:Xuan Jiang、Heng Ma
DOI:10.1055/s-2008-1072764
日期:2008.5
Oxazolidin-2-one was found to be a versatile and efficient ligand for the CuI-catalyzed amidation of aryl halides and the cyclization of ortho-halobenzanilides. Notably, the less active halides could also be applied successfully in the synthesis of benzoxazoles and benzothiazoles.
An efficient heterogeneous copper-catalyzed cyclization of o-haloanilides and metalsulfides has been achieved via the C–S coupling in DMF at 80 or 140 °C in the existence of an MCM-41-bound NHC-Cu(I) catalyst and then intramolecular condensation, delivering a wide range of substitutedbenzothiazoles in mostly good to high yields. This new MCM-41-NHC-CuI complex can facilely be obtained by a two-step