Selective C–H Bond Oxidation Catalyzed by the Fe-bTAML Complex: Mechanistic Implications
作者:Munmun Ghosh、Santanu Pattanayak、Basab B. Dhar、Kundan K. Singh、Chakadola Panda、Sayam Sen Gupta
DOI:10.1021/acs.inorgchem.7b00453
日期:2017.9.18
Nonheme iron complexes bearing tetradentate N-atom-donor ligands with cis labile sites show great promise for chemoselective aliphatic C–H hydroxylation. However, several challenges still limit their widespread application. We report a mechanism-guided development of a peroxidase mimicking iron complex based on the bTAML macrocyclicligand framework (Fe-bTAML: biuret-modified tetraamidomacrocyclic ligand)
Selective activation of secondary C–H bonds by an iron catalyst: insights into possibilities created by the use of a carboxyl-containing bipyridine ligand
4′-dicarboxylic acid), which could activate the C–H bonds of cycloalkanes with high secondary (2°) C–Hbond selectivity. A turnover number (TN) of 11.8 and a 30% yield (based on the H2O2 oxidant) were achieved during the catalytic oxidation of cyclohexane by 1 under irradiation with visiblelight. For the transformation of cycloalkanes and bicyclic decalins with both 2° and tertiary (3°) C–H bonds, 1 always preferred
在这项工作中,我们报告发现了一种含羧基的铁催化剂1(Fe II -DCBPY,DCBPY = 2,2'-联吡啶-4,4'-二羧酸),该催化剂可以活化环烷烃的C–H键具有较高的次级(2°)CH键选择性。在H2O2的催化氧化过程中达到了11.8的周转数(TN)和30%的收率(基于H 2 O 2氧化剂)。环己烷在可见光照射下,按1。对于具有2°和叔(3°)C–H键的环烷烃和双环十氢化萘的转化,1总是优选将2°C–H键氧化为相应的酮和醇产物;在7个示例中,2°/ 3°的比率介于78/22和> 99/1之间。用18 O同位素标记实验,ESR实验,PPh 3方法和过氧化氢酶方法表征了氧化过程中的反应过程。1的成功表明,除了使用体积较大的催化剂外,使用体积较小的分子铁络合物作为催化剂也可以实现较高的2°C–H键选择性。
Stereoselective oxidation of alkanes with m-CPBA as an oxidant and cobalt complex with isoindole-based ligands as catalysts
作者:Oksana V. Nesterova、Maximilian N. Kopylovich、Dmytro S. Nesterov
DOI:10.1039/c6ra14382b
日期:——
substrates (>98% for cis-1,2-DMCH) and highest cis/trans ratio of tertiary alcohols (products) of 56, under mild conditions. The best achieved yields of tertiary cis-alcohols were of 13.7 and 50.5%, based on the substrate (cis-1,2-DMCH) and the oxidant (m-CPBA) respectively. Kinetic experiments, high bond and stereoselectivity parameters, kinetic isotopeeffect of 7.2(2) in the oxidation of cyclohexane, and
具有通式[M C 6 H 4 C(NH 2)NC(ONCMe 2)2 } 2 ](NO 3)2的异吲哚核配体的两个配合物(M = Co表示1,M = Ni表示2)研究作为催化剂用于与轻度立体选择性氧化烷烃米氯过苯甲酸(米-CPBA)作为氧化剂和顺-1,2-二甲基环己烷(顺式-1,2- DMCH)作为主要模型底物。配合物1表现出显着的活性,并高度保留了底物的立体构型(顺式> 98%-1,2- DMCH)和最高的顺/反式的56(产品),在温和条件下的叔醇的比率。基于底物(顺式-1,2-DMCH)和氧化剂(m -CPBA),最佳的顺式叔醇收率分别为13.7和50.5%。动力学实验,高粘合和立体选择性的参数,在将环己烷氧化的7.2(2)动力学同位素效应,和掺入18从H 2 O 2 18 O支持Co的参与IV ø高价金属-氧中间体作为主要的C -H攻击物种。
Non‐Heme‐Type Ruthenium Catalyzed Chemo‐ and Site‐Selective C−H Oxidation
Herein, we developed a Ru(II)(BPGA) complex that could be used to catalyze chemo- and site-selective C-H oxidation. The described ruthenium complex was designed by replacing one pyridyl group on tris(2-pyridylmethyl)amine with an electron-donating amide ligand that was critical for promoting this type of reaction. More importantly, higher reactivities and better chemo-, and site-selectivities were
Arylruthenium(III) Porphyrin-Catalyzed C–H Oxidation and Epoxidation at Room Temperature and [Ru<sup>V</sup>(Por)(O)(Ph)] Intermediate by Spectroscopic Analysis and Density Functional Theory Calculations
作者:Ka-Pan Shing、Bei Cao、Yungen Liu、Hung Kay Lee、Ming-De Li、David Lee Phillips、Xiao-Yong Chang、Chi-Ming Che
DOI:10.1021/jacs.8b04470
日期:2018.6.6
metal catalysts for efficient oxidation of hydrocarbons and identification of the reactive intermediates in the oxidation catalysis are long-standing challenges. In the rapid hydrocarbon oxidation catalyzed by ruthenium(IV) and -(III) porphyrins, the putative Ru(V)-oxo intermediates remain elusive. Herein we report that arylruthenium(III) porphyrins are highly active catalysts for hydrocarbon oxidation