29964-62-3Relevant articles and documents
Diphosphine-palladium and -platinum complexes as catalysts for the Baeyer-Villiger oxidation of ketones: Effect of the diphosphine, oxidation of acyclic ketones, and mechanistic studies
Gavagnin, Roberta,Cataldo, Maurizio,Pinna, Francesco,Strukul, Giorgio
, p. 661 - 667 (1998)
A variety of Pd and Pt complexes of the type [(P-P)M(μ-OH)]22+ (M = Pd, Pt; P-P = a series of tetraphenyldiphosphines) were tested in the Baeyer-Villiger oxidation of ketones with hydrogen peroxide. The effect of the diphosphine-metal ring size on the catalytic activity indicates that the larger the ring, the better the catalyst and that, in general, Pt complexes are superior. The complex modified with P-P = dppb is the most active catalyst and allows for the first time the oxidation of a series of acyclic ketones. The corresponding migratory aptitude series is in full agreement with the one known for the stoichiometric organic reaction employing peracids as oxidants. A test of the reactivity of different peroxidic oxidants (H2O2, t-BuOOH, KHSO5, carbamide peroxide) shows that hydrogen peroxide is the most effective. A kinetic study of the oxidation of 2-methylcyclohexanone with [(dppb)-Pt(μ-OH)]22+ as the catalyst shows typical half-order dependence on the catalyst concentration, suggesting that the hydroxy dimer opens up to form the catalytically active species. The reaction is first order in ketone and hydrogen peroxide and is independent of the acidity of the system. The reaction is suggested to proceed via a quasi-peroxymetallacyclic intermediate and bears strong similarities to the stoichiometric organic reaction.
Tandem palladium-catalyzed cyclocarbonylation of isolimonene: A mechanistic investigation and theoretical calculations on the fully diastereoselective step
Lenoble, Geraldine,Lacaze-Dufaure, Corinne,Urrutigoity, Martine,Mijoule, Claude,Kalck, Philippe
, p. 791 - 797 (2004)
Cyclocarbonylation of isolimonene catalyzed by complexes of the type [HPd(SnCl3)L2] provides two cyclopentanone isomers (2a and 2b) containing two new stereogenic centers with a good diastereomeric excess (up to 69% with L2 = dppf). These results show that chiral phosphane ligands are not necessary to ensure asymmetric induction. The diastereomeric excess is due, in fact, to the substrate itself, assisted by the steric hindrance of the diphosphanes. A full characterization of the two isomers by 1H, 13C and DPFGSE NOE NMR spectroscopy gives all the signal assignations and all the positions of the substituents of interest on the chiral carbon atoms. In order to have a better understanding of the catalytic process, we also present a density functional study of the crucial intermediate species 4 involved in the proposed catalytic cycle. Our calculations show that there is no coordination of the C=C bond in an exo mode. Conversely, we have found a pentacoordinate species with a trigonal bipyramidal geometry in which the C=C bond is coordinated in an endo mode. Selected bond lengths and bond orders are reported. The calculated net charge distribution supports the cyclization process, which proceeds through a C-C(O) and a C-Pd coupling. A β-hydride elimination reaction of 4 provides the two 2a and 2b isomers. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Bicyclic Lactams Derived from Serine or Cysteine and 2-Methylpropanal
Bagum, Halima,Christensen, Kirsten E.,Genov, Miroslav,Moloney, Mark G.,Pretsch, Alexander,Pretsch, Dagmar,Shire, Bethany R.
supporting information, p. 378 - 382 (2020/02/27)
Bicyclic lactams may be prepared from serine or cysteine and 2-methylpropanal; the resulting S, N -heterocycles are more stable than the corresponding O, N -heterocycles but both are synthetic intermediates capable of further elaboration.
A double (mortars; concrete ; artificial stone) alkane dichloride method for the preparation of palladium complexes (by machine translation)
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Paragraph 0027; 0028; 0029; 0030; 0031, (2017/02/24)
The invention discloses a double (mortars; concrete ; artificial stone) alkane second palladium chloride complex preparation method, the method is:a, preparation chlorine arrowhead acid solution; b, the double (mortars; concrete ; artificial stone) alkane adding N, N-dimethyl formamide (mortars; concrete ; artificial stone) is made of the alkane-N, N-dimethyl formamide solution; three, under stirring condition to the double (mortars; concrete ; artificial stone) N of paraffins, N-dimethyl formamide solution adds by drops the chlorine arrowhead acid solution, stirring reaction after the completion of the dropping, cooling after-filtration, the filter cake obtained; four, washing the filter cake, the filter cake after washing is then subjected to vacuum drying, to get double (mortars; concrete ; artificial stone) alkane second palladium chloride complex. The invention directly the palladium source is palladium sponge, to double with the ligand chlorine arrowhead acid (mortars; concrete ; artificial stone) alkane in the solvent DMF in one-step synthesis target product, omits the intermediate palladium chloride, palladium chloride process for the preparation of acetonitrile, has the advantages of simple technique, cycle is short, low cost, and the like. (by machine translation)
