The borrowing hydrogen (BH) principle, also called hydrogen auto-transfer, is a powerful approach which combines transfer hydrogenation (avoiding the direct use of molecular hydrogen) with one or more intermediate reactions to synthesize more complex molecules without the need for tedious separation or isolation processes. The strategy which usually relies on three steps, (i) dehydrogenation, (ii) intermediate reaction, and (iii) hydrogenation, is an excellent and well-recognized process from the synthetic, economic, and environmental point of view. In this context, the objective of the present review is to give a global overview on the topic starting from those contributions published prior to the emergence of the BH concept to the most recent and current research under the term of BH catalysis. Two main subareas of the topic (homogeneous and heterogeneous catalysis) have been identified, from which three subheadings based on the source of the electrophile (alkanes, alcohols, and amines) have been consid...

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Advances in One-Pot Synthesis through Borrowing Hydrogen Catalysis

The synthesis of inorganic materials by biological systems is characterized by processes that occur at close to ambient temperatures, pressures and neutral pH. This is exemplified by biosilicification in marine organisms such as diatoms while laboratory-based synthesis of silica involves extreme temperature and pH conditions. We show here that silica and titania particles may be produced by challenging the fungus Fusarium oxysporum with aqueous anionic complexes SiF62− and TiF62− respectively. Extra-cellular protein-mediated hydrolysis of the anionic complexes results in the facile room temperature synthesis of crystalline titania particles while calcination at 300 °C is required for crystallization of silica.

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Fungus-mediated biosynthesis of silica and titania particles

An olefin polymerization process wherein monomer, diluent and catalyst are circulated in a continuous loop reactor and product slurry is recovered by means of a continuous product take off. The continuous product allows operating the reaction at significantly higher solids content in the circulating slurry. In a preferred embodiment, the slurry is heated in a flash line heater and passed to a high pressure flash where a majority of the diluent is separated and thereafter condensed by simple heat exchange, without compression, and thereafter recycled. Also an olefin polymerization process operating at higher reactor solids by virtue of more aggressive circulation.

High solids slurry polymerization

Novel lubricant compositions comprising polyalphaolefins are disclosed having high viscosity indices with low pour point. The compositions are characterized by a uniform molecular structure with low branch ratios. The invention describes a liquid lubricant composition comprising C 30 -C 1300 hydrocarbons, said composition having a branch ratio of less than 0.19, weight average molecular weight between 300 and 45,000 number average molecular weight between 300 and 18,000, molecular weight distribution between 1 an 5 and pour point below -15° C. 1-decene trimer comprising 9-methyl, 11-octylheneicosane and 11-octyldocosane is disclosed.

High viscosity index synthetic lubricant compositions

A process for oligomerizing alpha olefin to produce lubricant range hydrocarbon stock including the step of contacting said alpha olefin with a supported solid reduced Group VIB (e.g., chromium) catalyst under oligomerization conditions at a temperature of about 90° to 250° C. to produce liquid lubricant hydrocarbon. The product comprises the polymeric residue of linear C 6 -C 20 1-alkenes, said composition having a branch ratio of less than 0.19. The weight average molecular weight is between 420 and 45,000, number average molecular weight between 420 and 18,000, molecular weight distribution between 1 and 5 and pour point below -15° C. The hydrogenated lubricant range hydrocarbon product has viscosity index of about 130 to 280 and viscosity up to about 750 cS. The process is particularly useful where the starting alpha olefin consists essentially of olefinic hydrocarbon having 8 to 14 carbon atoms or mixtures thereof; wherein the process conditions include reaction temperature of about 100° to 180°; and wherein the support catalyst includes porous inert silica.

Process for manufacturing olefinic oligomers having lubricating properties

Polymers and production thereof

Marlex Catalyst Systems

Polymerization of Light Olefins over Nickel Oxide–Silica-Alumina

OLEFINS ARE CONVERTED BY CONTACTING A MIXTURE OF AT LEAST TWO DOUBLE BOND ISOMERS WITH AN OLEFIN REACTION CATALYST. OLEFINS ARE PRETREATED BY CONTACT WITH MAGNESIUM OXIDE PRIOR TO THE CONVERSION.

Conversion of olefins

A composition active for the conversion of olefins comprising magnesium oxide and an olefin disproportionation catalyst in admixture.

Robert L Banks

Papers

Polymers and production thereof

Marlex Catalyst Systems

Polymerization of Light Olefins over Nickel Oxide–Silica-Alumina

Conversion of olefins

Catalysts for conversion of olefins