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
atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles. Effectively working as the promoter in the alcohol oxidation, nitrile hydration, and cyclocondensation steps, CsOH is the best base for the reaction. A similar method can also be extended to the synthesis of substituted
A facile and versatile protocol for the one-pot PhI(OAc) 2 mediated divergent synthesis of quinazolines from 2-aminobenzylamine
作者:Moumita Saha、Prasun Mukherjee、Asish R. Das
DOI:10.1016/j.tetlet.2017.04.036
日期:2017.5
be the key reagent in absence or presence of catalytic amount of molecular iodine (I2)/zinc chloride (ZnCl2) to construct quinazoline scaffold from 2-aminobenzylamine and a variety of easily available aldehydes, aryl and aliphatic amines, aliphatic and aryl alcohols and nitriles. This protocol provides mild and robust conditions along with great versatility to synthesize 2-substituted quinazolines from
Cu/N-ligand/TEMPO catalytic system was first applied to the aerobic oxidative synthesis of heterocycles. As demonstrated, 2-substituted quinazolines and 4H-3,1-benzoxazines were synthesized efficiently from the one-pot reaction of aldehydes with 2-aminobenzylamines and 2-aminobenzyl alcohols, respectively, by employing CuCl/DABCO/4-HO-TEMPO as the catalysts and oxygen as the terminal oxidant.
Cu / N-配体/ TEMPO催化体系首先被用于杂环的好氧氧化合成。如所证明的,通过使用CuCl / DABCO / 4-HO-TEMPO分别由醛与2-氨基苄胺和2-氨基苄醇的一锅反应有效地合成了2-取代的喹唑啉和4 H -3,1-苯并恶嗪。作为催化剂,氧气作为末端氧化剂。