18803-09-3Relevant articles and documents
A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
Taylor, Nicholas P.,Gonzalez, Jorge A.,Nichol, Gary S.,García-Domínguez, Andrés,Leach, Andrew G.,Lloyd-Jones, Guy C.
, p. 721 - 729 (2022/01/04)
The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
Ligand-free palladium catalyzed phosphorylation of aryl iodides
Nowrouzi, Najmeh,Keshtgar, Saba,Bahman Jahromi, Enayatollah
, p. 348 - 350 (2016/01/12)
A reusable ligand-free palladium catalyzed phosphorylation of aryl iodides using PdCl2/tetrabutylammonium bromide is described. Functionalized triarylphosphines were obtained in good to excellent yields in the absence of external reductants and supporting ligands.
Phosphinodi(benzylsilane) PhP{(o -C6H4CH 2)SiMe2H}2: A versatile pSi 2Hx pincer-type ligand at ruthenium
Montiel-Palma, Virginia,Munoz-Hernandez, Miguel A.,Cuevas-Chavez, Cynthia A.,Vendier, Laure,Grellier, Mary,Sabo-Etienne, Sylviane
, p. 9798 - 9806 (2013/09/23)
The synthesis of the new phosphinodi(benzylsilane) compound PhP{(o-C 6H4CH2)SiMe2H}2 (1) is achieved in a one-pot reaction from the corresponding phenylbis(o- tolylphosphine). Compound 1 acts as a pincer-type ligand capable of adopting different coordination modes at Ru through different extents of Si-H bond activation as demonstrated by a combination of X-ray diffraction analysis, density functional theory calculations, and multinuclear NMR spectroscopy. Reaction of 1 with RuH2(H2)2(PCy 3)2 (2) yields quantitatively [RuH2{[η 2-(HSiMe2)-CH2-o-C6H 4]2PPh}(PCy3)] (3), a complex stabilized by two rare high order ε-agostic Si-H bonds and involved in terminal hydride/η2-Si-H exchange processes. A small free energy of reaction (ΔrG298 = +16.9 kJ mol-1) was computed for dihydrogen loss from 3 with concomitant formation of the 16-electron species [RuH{[η2-(HSiMe2)-CH 2-o-C6H4]PPh[CH2-o-C 6H4SiMe2]}(PCy3)] (4). Complex 4 features an unprecedented 29Si NMR decoalescence process. The dehydrogenation process is fully reversible under standard conditions (1 bar, 298 K).
