imine-based nonheme iron(II) complexes (LX)2Fe(OTf)2 has been prepared, characterized, and employed as C–H oxidationcatalysts. Ligands LX (X = 1, 2, 3, and 4) stand for tridentate imine ligands resulting from spontaneous condensation of 2-pycolyl-amine and 4-substituted-2-picolyl aldehydes. Fast and quantitative formation of the complex occurs just upon mixing aldehyde, amine, and Fe(OTf)2 in a 2:2:1
制备,表征了一系列基于亚胺的非血红素铁(II)配合物(LX)2 Fe(OTf)2,并用作CH氧化催化剂。配体LX(X = 1,2,3,和4)静置由2- pycolyl胺和4-取代的-2-吡啶甲基醛自发缩合得到的三齿配体的亚胺。仅在乙腈溶液中以2:2:1的比例混合醛,胺和Fe(OTf)2时,即可快速,定量地形成络合物。(L1)2 Fe(OTf)(ClO 4)和(L 3)2 Fe(OTf)2被报道,显示出低旋转的八面体铁中心,其配体以子午线的方式排列。1 H NMR分析表明固态结构和自旋态保留在溶液中。这些分析还表明存在胺-亚胺互变异构平衡。(LX)2 Fe(OTf)2利用H 2 O 2有效催化烷基C–H键的氧化作为末端氧化剂。亚胺配体的电子性质的控制对氧化过程的效率和选择性只有很小的影响。进行了一项机理研究,提供了C–H氧化是基于金属的证据。反应在羟基碳上以立体保留的方式发生,并在叔碳氢键上
Aerobic Oxidative Coupling of Amines by Carbon Nitride Photocatalysis with Visible Light
作者:Fangzheng Su、Smitha C. Mathew、Lennart Möhlmann、Markus Antonietti、Xinchen Wang、Siegfried Blechert
DOI:10.1002/anie.201004365
日期:2011.1.17
Coupling on sunshine: A simple and efficient synthesis of benzoxazoles, benzimidazoles, and benzothiazoles is realized through a one‐pot preparation driven by a photocatalyticcascade reaction. Carbon nitride and visiblelight are employed to achieve this metal‐free aerobic oxidation of amines to imines (see scheme; mpg‐C3N4=mesoporous graphite carbon nitride).
阳光下的耦合:通过光催化级联反应驱动的一锅法制备,可实现苯并恶唑,苯并咪唑和苯并噻唑的简单有效合成。氮化碳和可见光可用于实现胺向亚胺的无金属需氧氧化(请参阅方案; mpg-C 3 N 4 =中等石墨氮化碳)。
Highly active and selective gold catalysts for the aerobic oxidative condensation of benzylamines to imines and one-pot, two-step synthesis of secondary benzylamines
heterocyclic methanamines undergo oxidative condensation. 1-Phenylethanamine and diphenylmethanamine form imines with much less selectivity than benzylamines due to the unfavourable steric hindrance introduced by the substituents at the α-carbon. Secondary and tertiary dibenzyl and tribenzylamines form N-benzylidene benzylamines accompanied with aromatic ketones and oximes arising from C–N bond rupture
We have discovered a new class of cooperative catalytic system, consisting of heterogeneous polymer-immobilized bimetallic Pt/Ir alloyed nanoclusters (NCs) and 4-tert-butylcatechol, for the aerobic oxidation of amines to imines under ambient conditions. After optimization, the desired imines were obtained in good to excellent yields with broad substrate scope. The reaction rate was determined to be
2D sp
<sup>2</sup>
Carbon‐Conjugated Porphyrin Covalent Organic Framework for Cooperative Photocatalysis with TEMPO
作者:Ji‐Long Shi、Rufan Chen、Huimin Hao、Cheng Wang、Xianjun Lang
DOI:10.1002/anie.202000723
日期:2020.6.2
2D covalentorganicframeworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2 carbon-conjugated porphyrin-based covalentorganicframework (Por-sp2 c-COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light-emitting diodes (LEDs). Highly selective conversion of amines into