Methods for the synthesis of harmine comprise reacting harmaline with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in the presence of a diacid catalyst. In an embodiment, the synthesis is carried out using a reaction mixture of harmaline, DDQ, THF solvent, and succinic acid; the reaction is carried out under an inert atmosphere with refluxing for a period of 4-12 hours.

The present invention relates to the field of nanotechnology, more specifically to the production of gold nanoparticles (AuNPs) from plant extracts derived from leaves, stems, seeds, flowers, fruits or latex from plant species such as Colliguaja salicifolia, Pittosporum Undulatum, Acca sellowiana, Ugni molinae and Colliguaja integerrima, in which naturally occurring biocatalysts are possessed by these plants. The invention also relates to the gold nanoparticles obtained from said plants as well as to said natural biocatalysts.

A microencapsulated polyaddition catalyst comprises a capsule core, containing polyaddition catalyst, and an acrylic copolymer capsule shell, the acrylic copolymer comprising copolymerized units of an intermolecular anhydride of an ethylenically unsaturated C.sub.3-C.sub.12 carboxylic acid. The polyaddition catalyst is selected from acyclic tertiary amines, alicyclic tertiary amines, N-alkylimidazoles, phosphines and organic metal salts. It is suitable for catalysing the reaction of a polyol compound with a polyisocyanate compound. The polyaddition catalyst is released by a chemical stimulus, such as on contact with polyols or water, for example.

The invention relates to a catalyst comprising a support based on alumina or silica or silica-alumina, at least one group VIII element, at least one group VIB element and at least one organic compound of formula (I) ##STR00001##
in which R.sub.1 is a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, R.sub.2 and R.sub.3 are chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, X is chosen from an oxygen atom or a sulfur atom except when R.sub.2 and R.sub.3 represent a hydrogen atom, in which case X is an oxygen atom, Y is chosen from a hydrogen atom, a hydrocarbon-based radical comprising from 1 to 12 carbon atoms or a unit —C(O)R.sub.4, R.sub.4 being chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms.

A highly active hydroprocessing catalyst that comprises a doped support having been impregnated with a metal-impregnation solution, comprising a complexing agent and a hydrogenation metal, and filled with an organic additive blend. The catalyst is made by providing a doped support particle followed by impregnating the doped support particle with a metal impregnation solution that contains both a hydrogenation metal component and a complexing agent component to provide a metal-impregnated doped support particle. The metal-impregnated doped support particle is dried, but not calcined, and impregnated with an organic additive blend component.

A highly active hydroprocessing catalyst that comprises an inorganic oxide support particle having been impregnated with a metals-impregnation solution comprising a complexing agent and a hydrogenation metal that is further incorporated with an organic additive blend.

The present invention relates to a simple process for regenerating a hydroformylation catalyst consisting of a heterogenized catalyst system on a support consisting of a porous ceramic material. The invention also relates to a process for the start-up of the hydroformylation reaction after regeneration according to the invention.

Disclosed herein are methods for the preparation of porous metal oxide materials, including metal oxide xerogels and metal oxide aerogels. Methods for preparing porous metal oxide materials can comprise (i) reacting a metal alkoxide with water in the presence of a catalyst system to form a partially hydrolyzed sol, (ii) contacting the partially hydrolyzed sol with a base catalyst and a non-aqueous solvent to form a precursor gel; and (iii) drying the precursor gel to form the porous metal oxide material. The catalyst system employed in step (i) comprises a combination of a weak acid and a strong acid.

A highly active hydroprocessing catalyst that comprises a doped support impregnated with at lease one hydrogenation metal component and filled with an organic additive blend. The catalyst is made by providing a doped support particle followed by impregnating the doped support particle with a metal impregnation solution to provide a metal-impregnated doped support particle. The metal-impregnated doped support particle is dried but not calcined and impregnated with an organic additive blend component.

A method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture wherein a weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4 and an equivalent molar ratio of titanium-containing compound to peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt. % to about 20 wt. % water and the solubilized titanium mixture to form an addition product and drying the addition product by heating to a temperature in a range of from about 50° C. to about 150° C. and maintaining the temperature in the range of from about 50° C. to about 150° C. for a time period of from about 30 minutes to about 6 hours to form a pre-catalyst.