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Catalysts at a solid surface (nanomaterial-based catalysts) involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals utilize 3d and 4s electrons for bonding). This has the effect of increasing the concentration of the reactants at the catalyst surface and also weakening of ...
Whereas transition metals sometimes attract most of the attention in the study of catalysis, small organic molecules without metals can also exhibit catalytic properties, as is apparent from the fact that many enzymes lack transition metals. Typically, organic catalysts require a higher loading (amount of catalyst per unit amount of reactant ...
Transition metal oxides are compounds composed of oxygen atoms bound to transition metals. They are commonly utilized for their catalytic activity and semiconducting properties. Transition metal oxides are also frequently used as pigments in paints and plastics, most notably titanium dioxide. Transition metal oxides have a wide variety of ...
Besides using two transition metal catalysts, synergistic catalysis can also be carried out by utilizing one transition metal catalyst in combination with an organocatalyst. Here the synergistic α-allylation of aldehydes was accomplished by utilizing a transition metal complex in combination with a chiral amine catalyst.
Common Lewis acid catalysts are based on main group metals such as aluminum, boron, silicon, and tin, as well as many early (titanium, zirconium) and late (iron, copper, zinc) d-block metals. The metal atom forms an adduct with a lone-pair bearing electronegative atom in the substrate, such as oxygen (both sp 2 or sp 3), nitrogen, sulfur, and ...
Palladium catalysts can be problematic for the pharmaceutical industry, which faces extensive regulation regarding heavy metals. Many pharmaceutical chemists attempt to use coupling reactions early in production to minimize metal traces in the product. [8] Heterogeneous catalysts based on Pd are also well developed. [9]
A metal-phosphine complex is a coordination complex containing one or more phosphine ligands. Almost always, the phosphine is an organophosphine of the type R 3 P (R = alkyl, aryl). Metal phosphine complexes are useful in homogeneous catalysis.
Rhodium(I) and rhodium(III) salts are the most common catalysts for hydrosilylation. Asymmetric induction may be conferred by chiral PYBOX ligands. [16] (11) Transition metal catalyzed reductions are subject to the spatial properties of the chiral ligand bound to the metal center that determine the sense and extent of enantioselectivity.