35520-81-1Relevant academic research and scientific papers
Room temperature asymmetric Pd-catalyzed methoxycarbonylation of norbornene: Highly selective catalysis and HP-NMR studies
Blanco, Carolina,Godard, Cyril,Zangrando, Ennio,Ruiz, Aurora,Claver, Carmen
experimental part, p. 6980 - 6991 (2012/07/14)
Palladium complexes bearing monodentate and bidentate phosphine ligands (1-7) were synthesised and used as catalyst precursors in the methoxycarbonylation of norbornene. The catalytic systems bearing ligands 1, 3 and 4 afforded excellent conversions (>99%) and selectivity of the ester (>99%). NMR investigations showed that using complex 1a as the precursor resulted in the protonated phosphine, 1-H+, being formed under catalytic conditions and thus the addition of acid is not required for the activation of this system since the reaction involving the precursor with methanol under CO pressure produces 2 equivalents of HCl and leads to the formation of the active species. The protonation of ligand 4 under methoxycarbonylation conditions was also observed and the diprotonated diphosphine was isolated and characterised. This compound was tested as a ligand and acid source in a catalysis and provided excellent conversion and high selectivity to the ester.
Unprecedent chemo- and stereoselective palladium-catalysed methoxycarbonylation of norbornene
Blanco, Carolina,Ruiz, Aurora,Godard, Cyril,Fleury-Bregeot, Nicolas,Marinetti, Angela,Claver, Carmen
experimental part, p. 1813 - 1816 (2011/02/26)
Catalytic systems able to control chemoand stereoselectivity have been tested in the palladium-catalysed methoxycarbonylation of norbornene. An enantioselectivity of up to 40% was obtained.
The reaction of some polycyclic halides with lihium p,p'-di-tert-butylbiphenyl
Stapersma, J.,Kuipers, P.,Klumpp, G. W.
, p. 213 - 218 (2007/10/02)
3-chloroquadricyclane (1), 2(4)-chlorosemibullvalene (2a), a series of 2-norbornyl halides and 4,4-dichlorotetracyclo2,8.03,6>octane (4) have been treated with lithium p,p'-di-tert-butylbiphenyl.Lihiation (2, norbornyl halides), lithiation with rearrangement (4) and lithiation with rearrangement followed by reduction to the cycloheptatrienyl trianion (1 -> 14) have been found to occur.
