1,721,109 research outputs found
Non-covalent Activation of a Titanium(IV) Oxygen-Transfer Catalyst
No full textKinetic studies, in combination with theoretical calculations,
support a mechanism in which the coordination of one alcohol molecule activates a Ti pre-catalyst. The alcohol coordination has a twofold action: it switches the Ti peroxo complex to an active geometry, and it stabilises the reactive peroxo intermediate through hydrogen bonding
Iridium-mediated Bond Activation and Water Oxidation as an Exemplary Case of CARISMA, A European Network for the Development of Catalytic Routines for Small Molecule Activation
Full text linkCARISMA is a currently running COST Action that pools leading European experts in computational and experimental chemistry to foster synergies for developing new catalytic processes for the transformation of abundant small molecules such as water, carbon dioxide, or ammonia into high-value chemicals and energy-relevant products. CARISMA promotes new collaborations, exchange of knowledge and skills, frontier training to young as well as established researchers, and a platform for the advancement of theoretical and experimental research in an iterative process, comprised of expertise in various connate domains including synthesis, catalysis, spectroscopy, kinetics, and computational chemistry. These interactions stimulate the discovery of new and efficient catalytic processes, illustrated in the second part of this contribution with the collaborative development of powerful iridium-based complexes for bond activation and water oxidation catalysis
Revisiting the HammettρParameter for the Determination of Philicity: Nucleophilic Substitution with Inverse Charge Interaction
No full textIn oxygen transfer (OT) reactions the inversion of the ρ value is not representative of a change in mechanism. Substituents bonded to aromatic sulfoxides have the opposite effect on the rates of oxidation depending on whether the reaction is dominated by electrostatic or orbital-overlap effects
Small molecule activation
No full textThe activation of small molecules has become an increasingly popular area of research over the last years, and there are many reasons to be captivated by this fascinating topic
Second-Generation Tris(2-pyridylmethyl)amine–Zinc Complexes as Probes for Enantiomeric Excess Determination of Amino Acids
No full textSelf-assembly through imine condensation chemistry in combination with metal coordination is becoming one of the leading strategies for the preparation of stereodynamic probes for the determination of enantiomeric excess. Recently, we reported a novel molecular architecture based on a modified tris(2-pyridylmethyl)amine–zinc(II) complex [TPMA = tris(2-pyridylmethyl)amine] that is able to function as an optical probe for the determination of the enantiomeric excess of amino acids. Herein, we report on how a slight modification of the TPMA ligand enhances both the dichroic response and the stability of the system. The novel probe provides a much higher dichroic signal compared with the previously reported system
Atropisomeric Sulfur-compounds In Organic-synthesis - Generation and Reactions of the Carbanions of Dinaphtho[2,1-d-1',2'-f][1,3]dithiepine and Its Oxides
No full textOxidation of dinaphtho[2,1-d:1′,2′-f][1,3]dithiepine (2) gives a single diastereoisomeric sulphoxide (1) which reacts diastereospecifically with electrophiles at variance with the unoxidized substrate (2) and other combinations of oxides (4),(6), and (7) which afford diastereoisomeric mixtures of products
Anti-1,4,5,8-tetrahydro-1,4-5,8-dimethanonaphthalene (sesquinorbornadiene), A Molecule With 3 Parallel, Coplanar, and Interacting Double-bonds
No full textAnti-1,4,5,8-Tetrahydro-1,4;5,8-dimethanonaphthalene (sesquinorbornadiene)(1), a molecule possessing six electrons distributed in three parallel double bonds set in one plane and within an interacting through-space distance, has been synthesized
Catalysis of oxo transfer to prochiral sulfides by oxovanadium(V) compounds that model the active center of haloperoxidases
No full textA new class of vanadium-based chiral catalysts—trigonal-bipyramidal oxovanadium(V) complexes containing chiral tridentate amino-bis(alcoholate) ligands—modeling the active center of vanadate-dependent haloperoxidases have been employed in the chiral induction of oxo transfer, by organic hydroperoxides, to prochiral thioethers to yield chiral sulfoxides (see scheme). Activation of the peroxide is achieved by coordination to vanadium
- …
