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。
A biomass-derived N-doped porous carbon catalyst for the aerobic dehydrogenation of nitrogen heterocycles
作者:Jing-Jiang Liu、Fu-Hu Guo、Fu-Jun Cui、Ji-Hua Zhu、Xiao-Yu Liu、Arif Ullah、Xi-Cun Wang、Zheng-Jun Quan
DOI:10.1039/d1nj05411b
日期:——
superior catalytic performance in the aerobic dehydrogenation of various heterocyclic nitrogen compounds (49 examples, up to 96% yield), similar to that of C3N4 and GO. Characterization by TEM, BET and XPS accompanied by the EPR analysis revealed that the enhanced catalytic properties of NC came from its high activation ability for both O2 and heterocyclic nitrogen, attributed to the porous structure and
N 掺杂的多孔碳 (NC) 是由甘蔗渣合成的,甘蔗渣是一种可持续且广泛使用的生物质废物。优选的 NC 样品具有发达的多孔结构、类似石墨烯的表面形态和不同的 N 种类。更重要的是,多相碳催化剂在各种杂环氮化合物的有氧脱氢反应中表现出优异的催化性能(49个例子,产率高达96%),类似于C 3 N 4和GO。TEM、BET 和 XPS 表征以及 EPR 分析表明,NC 的增强催化性能来自其对 O 2和杂环氮的高活化能力,分别归因于多孔结构和吡啶 N (N-6) 物种.
Highly Efficient One-Pot Synthesis of 2-Substituted Quinazolines and 4<i>H</i>-Benzo[<i>d</i>][1,3]oxazines<i>via</i>Cross Dehydrogenative Coupling using Sodium Hypochlorite
describes a catalyst-free synthesis of 2-substitutedquinazolines and 4H-benzo[d][1,3]oxazines using commericially available sodiumhypochlorite as oxidant. Operational simplicity, mild reaction conditions and the ability to construct structurally diverse 2-quinazolines and 2-substituted4H-benzo[d][1,3]oxazines by this method render it to be a practical alternative for the synthesis of these heterocycles
该通报描述了使用市售的次氯酸钠作为氧化剂的无催化剂合成2-取代的喹唑啉和4 H-苯并[ d ] [1,3]恶嗪。操作简便,反应条件温和以及通过该方法构造结构上不同的2-喹唑啉和2-取代的4 H-苯并[ d ] [1,3]恶嗪的能力使其成为合成这些杂环的实用选择。
Ring-chain tautomerism in 2-substituted 1,2,3,4-tetrahydroquinazolines A 1H, 13C and 15N NMR study
作者:Jari Sinkkonen、Kirill N. Zelenin、Abdul-Kadir A. Potapov、Igor V. Lagoda、Valeriy V. Alekseyev、Kalevi Pihlaja
DOI:10.1016/s0040-4020(03)00148-0
日期:2003.3
1H, 13C and 15N NMR spectroscopy. The ketone, as well as the alkyl aldehyde, derivatives were found to favor exclusively ring forms, whereas tautomeric equilibria were observed for aryl aldehyde derivatives. For para-phenyl substituted compounds, good linear correlations were found between the Hammett–Brown σ+ parameter and (K=[ring]/[chain]) and also between σ+ and δNC (NC nitrogen chemical shift)