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。
Alkane oxidation catalysed by a self-folded multi-iron complex
作者:Magi Mettry、Melissa Padilla Moehlig、Adam D. Gill、Richard J. Hooley
DOI:10.1080/10610278.2016.1177184
日期:2017.2.1
electrophilic CH oxidation catalyst. This catalyst oxidises unactivated hydrocarbons including simple, linear alkanes under mild conditions in good yields with selectivity for the oxidation of secondary CH bonds. Control complexes containing a single metal centre are incapable of oxidising unstrained linear hydrocarbons, indicating that participation of multiple centres aids the CH oxidation of challenging
Functionalisation of saturated hydrocarbons. part x.1 a comparative study of chemical and electrochemical processes (gif and gif-orsay systems) in pyridine in acetone and in pyridine-co-solvent mixtures
Six saturatedhydrocarbons (cyclohexane, 3-ethylpentane, methylcyclopentane, - and -decalin and adamantane) were oxidised by the GifIV system (iron catalyst, oxygen, zinc, carboxylic acid) and its electrochemical equivalent (Gif-Orsaysystem). Results obtained using various solvents (pyridine, acetone, pyridine-acetone mixtures) were similar for both systems. Total or partial replacement of pyridine
Anaerobic functionalization of remote unactivated carbon-hydrogen bond by polyoxometalates
作者:Craig L. Hill、Roman F. Renneke、Lucille Combs
DOI:10.1016/s0040-4020(01)86244-x
日期:1988.1
The excitedstates of a representative heteropolytungstate. α-PW12O403-, and a representative Isopotytungstate, W10O324-, accessible with near UV or blue light, oxidize alkanes and conventionally far more reactive organic molecules including alcohols, alkenes, N-alkylacetamides, and Ketones. at comparable rates. One or more of the latter three types of compounds are produced upon irradiation of acetonitrile
The alkylation reaction is considered to involve the C[bond]Hactivation of cycloalkanes with GaCl(3) at the tertiary center followed by the migration of carbocations and electrophilic aromatic substitution yielding thermodynamically stable products. The stereochemistry of the reaction reveals that GaCl(3) activates the equatorial tertiary C[bond]H rather than the axial tertiary C[bond]H.