13019-30-2Relevant articles and documents
Saturated 5-Membered Ring Conformations 2 - 1H NMR Study of Protonated N-Methylpyrrolidines
Infarnet, Y.,Duplan, J. C.,Huet, J.
, p. 90 - 93 (1981)
The 1H NMR spectra of the protonated and unprotonated forms of cis- and trans-N-methylhexahydroisoindoline, of 1,3,3,4,4-pentamethylpyrrolidine and of 1,3,3-trimethylpyrrolidine were analyzed.The coupling constants between the NH+ and the CH protons α to the nitrogen allowed the study of the conformation of the cyclic systems in pseudorotation.
Solubilized zirconocene dihydride as a promotor of alkene coupling reactions
Wipf,Wang
, p. 8237 - 8241 (2000)
The THF-soluble bis(methoxyethyl)zirconocene dihydride 3 displayed novel reactivity patterns and was used to reductively couple alkenes, dienes, and enynes. A plausible mechanism involves the formation of a 14-electron zirconium(II) and zirconacyclopentane species. (C) 2000 Published by Elsevier Science Ltd.
Carbonylation of ethylenically unsaturated compounds
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Page/Page column 37; 38, (2016/06/01)
A process for the carbonylation of ethylenically unsaturated compounds including vinyl esters and a process for the production of 3-hydroxy propanoate esters or acids. The process comprises reacting said compound with carbon monoxide in the presence of a source of hydroxyl groups and of a catalyst system. The catalyst system is obtainable by combining: (a) a metal of Group 8, 9 or 10 or a compound thereof: and (b) a bidentate ligand of general formula (I): X1(X2)-Q2-A-R—B-Q1-X3(X4).
Phosphine ligands in the Palladium-catalysed methoxycarbonylation of ethene: Insights into the catalytic cycle through an HP NMR spectroscopic Study
De La Fuente, Veronica,Waugh, Mark,Eastham, Graham R.,Iggo, Jonathan A.,Castillon, Sergio,Claver, Carmen
experimental part, p. 6919 - 6932 (2010/08/07)
Novel cis-1,2-bis(di-tertbutyl-phosphinomethyl) carbocyclic ligands 6-9 have been prepared and the corresponding palladium complexes [Pd(O 3SCH3)(L-L)][O3SCH3] (L-L = diphosphine) 32-35 synthesised and characterised by NMR spectroscopy and Xray diffraction. These diphosphine ligands give very active catalysts for the palladium-catalysed methoxycarbonylation of ethene. The activity varies with the size of the carbocyclic backbone, ligands 7 and 9, containing four- and six-membered ring backbones giving more active systems. The acid used as co-catalyst has a strong influence on the activity, with excess trifluoroacetic acid affording the highest conversion, whereas excess methyl sulfonic acid inhibits the catalytic system. An in oper-ando NMR spectroscopic mechanistic study has established the catalytic cycle and resting state of the catalyst under operating reaction conditions. Although the catalysis follows the hydride pathway, the resting state is shown to be the hydride precursor complex [Pd(O3SCH3)(L-L)][O3SCH3], which demonstrates that an isolable/detectable hydride complex is not a prerequisite for this mechanism.