Regio- and Enantioselective Allylation of Phenols<i>via</i>Decarboxylative Allylic Etherification of Allyl Aryl Carbonates Catalyzed by (Cyclopentadienyl)ruthenium(II) Complexes and Pyridine-Hydrazone Ligands
作者:Léo Egger、Cecilia Tortoreto、Thierry Achard、David Monge、Abel Ros、Rosario Fernández、José M. Lassaletta、Jérôme Lacour
DOI:10.1002/adsc.201500534
日期:2015.10.12
(Cyclopentadienyl)tris(acetonitrile)ruthenium hexafluorophosphate [CpRu(CH3CN)3][PF6] in combination with pyridine-hydrazone ligands efficiently catalyzes the asymmetric decarboxylative allylic rearrangement of allylarylcarbonates. Formation of CO bonds with high regio- and enantioselectivity ratios (up to 95:5 and 98% ee) is obtained. Good stereocontrol of the pseudotetrahedral geometry of the CpRu
Tuning of the Properties of Transition-Metal Bispidine Complexes by Variation of the Basicity of the Aromatic Donor Groups
作者:Peter Comba、Michael Morgen、Hubert Wadepohl
DOI:10.1021/ic4004214
日期:2013.6.3
find broad application in the field of coordination chemistry, and the redox potentials of their transition-metal complexes are of importance in oxidation reactions by high-valent iron complexes, aziridination catalyzed by copper complexes, and imaging by 64Cu positron emission tomography tracers. Here, we show that the redox potentials and stability constants of the copper(II) complexes of 15 tetradentate
联吡啶(3,7-二氮杂双环[3.3.1]壬烷)是非常刚性和高度组织化的配体,在配位化学领域得到广泛应用,它们的过渡金属配合物的氧化还原电势在高氧氧化反应中很重要。价铁络合物,铜络合物催化的叠氮化和64 Cu铜正电子发射断层显像剂成像。在这里,我们显示了15个四齿联吡啶的铜(II)配合物的氧化还原电势和稳定性常数可以通过取代吡啶环来改变(氧化还原电势在约450 mV以上的变化和复合物稳定性在约10 mV以上的变化)日志单位)。还表明,这些变化可以通过p K a预测。吡啶基团的值以及取代基的哈米特参数,以及基于密度泛函理论的能量分解分析,还可以使人们准确地预测氧化还原电势和随之而来的配合物稳定性。结果表明,主要贡献来自于静电相互作用能,因此吡啶供体基团的部分电荷也与氧化还原电势相关。
Studies on the Mechanism of Action of 2-Formyl-4-pyrrolidinopyridine: Isolation and Characterization of a Reactive Intermediate
作者:Tarek Sammakia、T. Brian Hurley
DOI:10.1021/jo982281n
日期:1999.6.1
action of 2-formyl-4-pyrrolidinopyridine (FPP, 1a) which is a catalyst for the hydroxyl-directedmethanolysis of alpha-hydroxy esters. This species was initially designed to act as a nucleophilic catalyst; however, we have ruled out a nucleophilic mechanism by examining the activity of 6-substituted-FPP derivatives. These compounds are more hindered in the vicinity of the pyridine nitrogen than FPP itself