Journal ArticleDOI
Synthesis, characterization, and application of vanadium-salan complexes in oxygen transfer reactions.
Pedro Adão,João Costa Pessoa,Rui T. Henriques,Maxim L. Kuznetsov,Fernando Avecilla,Mannar R. Maurya,Umesh Kumar,Isabel Correia +7 more
Reads0
Chats0
TLDR
The V-Salen and V-salan complexes show higher activity and normally better selectivity in alkene oxidation and higherActivity and enantioselectivity for sulfoxidation than their parent V- salen complexes, therefore being an advantageous alternative ligand system for oxidation catalysis.Abstract:
We report the synthesis and characterization of several chiral salen- and salan-type ligands and their vanadium complexes, which are derived from salicylaldehyde or salicylaldehyde derivatives and chiral diamines (1R,2R-diaminocyclohexane, 1S,2S-diaminocyclohexane, and 1S,2S-diphenylethylenediamine). The structures of H2sal(R,R-chan)2+·2Cl−·(CH3)2CHOH·H2O (1c; H2sal(R,R-chan) = N,N′-salicyl-R,R-cyclohexanediaminium), Etvan(S,S-chen) (3c; Etvan(S,S-chen) = N,N′-3-ethoxy-salicylidene-S,S-cyclohexanediiminato), and naph(R,R-chen) (6c; naph(R,R-chen) = N,N′-naphthylidene-R,R-cyclohexanediiminato) were determined by single-crystal X-ray diffraction. The corresponding vanadium(IV) complexes and several other new complexes involving different salicylaldehyde-type precursors were prepared and characterized in the solid state and in solution by spectroscopic techniques: UV−vis, circular dichroism, electron paramagnetic resonance, and 51V NMR, which provide information on the coordination geometry. The salan comple...read more
Citations
More filters
Journal ArticleDOI
Enantioselective synthesis of sulfoxides: 2000-2009.
TL;DR: Oxidation with Chiral Oxaziridines 4309 1.2.1.
Journal ArticleDOI
Catalytic Applications of Vanadium: A Mechanistic Perspective.
Ryan R. Langeslay,David M. Kaphan,Christopher L. Marshall,Peter C. Stair,Peter C. Stair,Alfred P. Sattelberger,Massimiliano Delferro +6 more
TL;DR: Reactions catalyzed by homogeneous and supported vanadium complexes from 2008 to 2018 are summarized and discussed and insights into heterogeneous vanadium catalysis are provided when parallels can be drawn from the homogeneous literature.
Journal ArticleDOI
Catalytic Asymmetric Oxygenations with the Environmentally Benign Oxidants H2O2 and O2.
TL;DR: An overview of catalyst systems capable of conducting asymmetric oxygenative transformations of organic molecules and, in line with the major trend to sustainability, relying on green oxidants H2O2 and O2 as the ultimate oxygen source is given.
Journal ArticleDOI
Recent developments in penta-, hexa- and heptadentate Schiff base ligands and their metal complexes
Xiang Liu,Jean-René Hamon +1 more
TL;DR: The synthesis and structure of polydentate Schiff bases and their metal complexes is fascinating, because it reveals a great richness of structural, physico-chemical and catalytic properties as mentioned in this paper.
Journal ArticleDOI
Oxovanadium complexes in catalytic oxidations
TL;DR: In this paper, an overview on the application of oxovanadium complexes as catalysts or mediators for oxidations by molecular oxygen, peroxidative oxygenations (both including epoxidations), halogenations and carboxylations of aliphatic and aromatic hydrocarbons, and/or olefins, toward the syntheses of a variety of organic compounds, such as alcohols, ketones, epoxides, aldehydes, organohalides and orcarboxylic acids.
References
More filters
Journal ArticleDOI
Density‐functional thermochemistry. III. The role of exact exchange
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
Journal ArticleDOI
Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density
TL;DR: Numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, show that density-functional formulas for the correlation energy and correlation potential give correlation energies within a few percent.
Journal ArticleDOI
Quantum Calculation of Molecular Energies and Energy Gradients in Solution by a Conductor Solvent Model
Vincenzo Barone,Maurizio Cossi +1 more
TL;DR: In this paper, a new implementation of the conductor-like screening solvation model (COSMO) in the GAUSSIAN94 package is presented, which allows Hartree−Fock (HF), density functional (DF) and post-HF energy, and HF and DF gradient calculations: the cavities are modeled on the molecular shape, using recently optimized parameters, and both electrostatic and nonelectrostatic contributions to energies and gradients are considered.
Journal ArticleDOI
Molecular Interactions in Solution: An Overview of Methods Based on Continuous Distributions of the Solvent
Jacopo Tomasi,Maurizio Persico +1 more
Journal ArticleDOI
Energy‐adjusted ab initio pseudopotentials for the first row transition elements
TL;DR: In this paper, nonrelativistic and quasirelativistic ab−initio pseudopotentials representing the Ne−like X(Z−10)+ cores (X=Sc-Zn) of the first row transition metals and optimized (8s7p6d1f)/[6s5p3d1fa]‐GTO valence basis sets for use in molecular calculations have been generated.