95-10-3Relevant articles and documents
Supporting multiple organometallic catalysts on poly(norbornene) for cyanide addition to α,β-unsaturated imides
Madhavan, Nandita,Sommer, William,Weck, Marcus
experimental part, p. 1 - 7 (2011/03/16)
A two-catalyst system comprising of salen(AlCl) and pybox(ErCl3) complexes supported onto poly(norbornene) has been developed. As a proof of concept the activity of the two-catalyst system was gauged for the addition of cyanide to α,β-unsaturated imides which has been shown to follow a bimetallic mechanism. The activity of the supported two-catalyst system was significantly higher than catalytic systems derived from mixtures of the two catalysts. In addition, the co-polymer could be readily recovered and reused up to 3 cycles without significant loss in conversions and yields. Nevertheless, a decrease in enantioselectivity of the cyanide adduct was observed with each subsequent cycle indicating some loss in catalytic selectivity. The reported strategy opens up avenues for supporting multiple catalysts on the same polymer backbone for catalyst-based one-pot cascade reactions.
Urea and Thiourea Derivatives Based on Amines of the Norbornene Series
Kas'yan, A. O.,Krasnovskaya, O. Yu.,Okovityi, S. I.,Kas'yan, L. I.
, p. 311 - 319 (2007/10/03)
Electron density distribution in molecules of amino derivatives of norbornene, exo- and endo-5-aminomethylbicyclohept-2-ene, exo-5-aminomethyl-endo-5-methylbicyclohept-2-ene, and their epoxy derivatives was studied by spectral methods (IR and 1H, 13C, and two-dimensional NMR spectroscopy) and by semiempirical (AM1) quantum-chemical calculations.The reactivity of amines was preliminary estimated from the calculated parameters: proton affinity and energies of localized molecular orbitals.The nucleophilic properties of the amines were studied in reactions with acyclic, alicyclic, and aromatic isocyanates and isothiocyanates.In the series of potentially bioactive ureas and thioureas, criteria have been formulated for ascribing the exo and endo structures to these compounds on the basis of the 1H NMR spectra.
Asymmetric Diels-Alder Reaction Using (S)-Pyroglutamic Acid Derivatives as Chiral Dienophiles
Ikota, Nobuo
, p. 2219 - 2221 (2007/10/02)
Asymmetric Diels-Alder reaction of cyclopentadiene with chiral dienophiles (3) derived from (S)-pyroglutamic acid derivatives was performed in the presence of a Lewis acid such as diethylaluminium chloride in toluene to afford the cycloadducts with high diastereoselectivity.Keywords asymmetric reaction; Diels-Alder reaction; (S)-pyroglutamic acid; chiral dienophile; diethylaluminium chloride; (2+4)cycloaddition
