Niacin as a Potent Organocatalyst towards the Synthesis of Quinazolines Using Nitriles as C-N Source
作者:Raghuram Gujjarappa、Nagaraju Vodnala、Velma Ganga Reddy、Chandi C. Malakar
DOI:10.1002/ejoc.201901651
日期:2020.2.21
An organocatalyzed protocol has been described for the comprehensive synthesis of 2‐substituted quinazolines usingnitriles as C–N source. The developed reaction conditions are suitable for a wide range of substrates providing the desired products in excellent yields.
Copper-catalyzed domino reaction between 1-(2-halophenyl)methanamines and amidines or imidates for the synthesis of 2-substituted quinazolines
作者:Mohamed A. Omar、Jürgen Conrad、Uwe Beifuss
DOI:10.1016/j.tet.2014.02.066
日期:2014.5
between 1-(2-bromophenyl)methanamines and amidines using K3PO4 as the base, pivalic acid as the additive, and aerial oxygen as the oxidant gives access to substituted quinazolines in a single step with yields in the range between 43 and 90%. It is assumed that the reaction proceeds as a Cu(I)-catalyzed intermolecular N-arylation followed by an intramolecularnucleophilic substitution and a Cu(II)-catalyzed
以K 3 PO 4为碱,新戊酸为添加剂,空气中的氧气为氧化剂的1-(2-溴苯基)甲胺和am之间的CuI催化的多米诺反应使一步反应可得到取代的喹唑啉范围介于43%和90%之间。假定该反应以Cu(I)催化的分子间N-芳基化进行,然后进行分子内亲核取代和Cu(II)催化的氧化。am可以被酰亚胺取代,反应也可以与1-(2-碘苯基)甲胺一起进行。
Copper-Catalyzed Synthesis of Quinazolines in Water Starting from o-Bromobenzylbromides and Benzamidines
作者:Chandi C. Malakar、Alevtina Baskakova、Jürgen Conrad、Uwe Beifuss
DOI:10.1002/chem.201200583
日期:2012.7.16
Water makes it possible: The Cu2O‐catalyzed reaction between easily available o‐bromobenzylbromides and benzamidines by using Cs2CO3 as the base and N,N′‐dimethylethylenediamine (DMEDA) as the additive in water as the solvent gives access to substituted quinazolines in a single step with yields ranging from 57 to 85 % (see scheme).
水使成为可能:通过使用Cs 2 CO 3作为碱和N,N'-二甲基乙二胺(DMEDA)作为在水中的添加剂作为溶剂,Cu 2 O催化易得的邻溴代溴化苄与苄am之间的反应一步即可取代取代的喹唑啉,产率为57%至85%(请参阅方案)。
Palladium-catalyzed carbonylative synthesis of quinazolines: Silane act as better nucleophile than amidine
A palladium-catalyzed reductive carbonylation reaction has been developed for the synthesis of quinazolines. With N-(2-iodophenyl)benzimidamide as starting materials, a series of quinazolines were obtained through the aromatic aldehyde intermediates in moderate to good yields with good functional group compatibilities. In this system, silane act as better nucleophile than amidine.
Assembly of 4H-chromenes, imidazobenzothiazines and quinazolines via copper-catalyzed domino reactions using 2-halobenzyl tosylates as substrates
作者:Mohamed A. Omar、Jürgen Conrad、Uwe Beifuss
DOI:10.1016/j.tet.2014.06.071
日期:2014.9
The use of 2-halobenzyl tosylates as substrates in copper-catalyzed domino intermolecular substitution/intramolecular arylation processes for the efficient and selective preparation of heterocycles is reported for the first time. Reaction of 2-halobenzyl tosylates with beta-ketoesters delivers 4H-chromenes with yields ranging between 59 and 89%. Imidazobenzothiazines are formed with yields up to 82% upon reaction of 2-halobenzyl tosylates with 2-mercaptoimidazoles. When 2-halobenzyl tosylates are reacted with benzamidines the corresponding quinazolines are obtained. (C) 2014 Elsevier Ltd. All rights reserved.