Organic hydrogenation reactions

Nickel and Platinum—These two metals (in the form of Raney nickel and Pt-black) are used for electrocatalytic organic hydrogenation reactions (i.e., the electrochemical generation of hydrogen on the catalytically active, high surface area cathode followed by the chemical reaction of adsorbed hydrogen with the organic substrate). 

By 1930 Carleton Elhs, who worked on organic hydrogenation reactions and the chemistry of petroleum derivatives, was able to publish a book that included a literature survey of the recent developments in hydrogenation reactions and catalysts. ... 

In 1931 Homer Adkins came to the conclusion that Raney nickel was better than any other nickel catalyst then available for organic hydrogenation reactions, as well as being more convenient to use. He described the new catalyst in a 1932 paper,and it was soon being widely used in other laboratories. Adkins was one of the first to study the catalyst extensively for a wider range of hydrogenation reactions. 

Can the byproduct be subjected to further reaction and its value upgraded For example, most organic chlorination reactions produce hydrogen chloride as a byproduct. If this cannot be sold, it... 

The equilibrium constant for this reaction decreases with increase in temperature but the higher temperature is required to achieve a reasonable rate of conversion. Hydrogen chloride is now being produced in increasing quantities as a by-product in organic chlorination reactions and it is economic to re-convert this to chlorine. 

Cyclohexane, produced from the partial hydrogenation of benzene [71-43-2] also can be used as the feedstock for A manufacture. Such a process involves selective hydrogenation of benzene to cyclohexene, separation of the cyclohexene from unreacted benzene and cyclohexane (produced from over-hydrogenation of the benzene), and hydration of the cyclohexane to A. Asahi has obtained numerous patents on such a process and is in the process of commercialization (85,86). Indicated reaction conditions for the partial hydrogenation are 100—200°C and 1—10 kPa (0.1—1.5 psi) with a Ru or zinc-promoted Ru catalyst (87—90). The hydration reaction uses zeotites as catalyst in a two-phase system. Cyclohexene diffuses into an aqueous phase containing the zeotites and there is hydrated to A. The A then is extracted back into the organic phase. Reaction temperature is 90—150°C and reactor residence time is 30 min (91—94). 

AH of the commercial inorganic peroxo compounds except hydrogen peroxide are described herein, as are those commercial organic oxidation reactions that are beheved to proceed via inorganic peroxo intermediates. Ozonides and superoxides are also included, but not the dioxygen complexes of the transition metals. 

Hydrogenation reactions, particularly for the manufacture of fine chemicals, prevail in the research of three-phase processes. Examples are hydrogenation of citral (selectivity > 80% [86-88]) and 2-butyne-l,4-diol (conversion > 80% and selectivity > 97% [89]). Eor Pt/ACE the yield to n-sorbitol in hydrogenation of D-glucose exceeded 99.5% [90]. Water denitrification via hydrogenation of nitrites and nitrates was extensively studied using fiber-based catalysts [91-95]. An attempt to use fiber-structured catalysts for wet air oxidation of organics (4-nitrophenol as a model compound) in water was successful. TOC removal up to 90% was achieved [96]. 

One of the most common heterogeneous organic reactions in the fine chemicals and the specialty chemicals industries is the hydrogenation of carbon-carbon multiple bonds. It is so common that an entire array of specialty catalysts has been developed to accomplish specific hydrogenation reactions. An important goal in this field is selectivity. However, when relatively large quantities of chemicals are produced, concerns also embrace economy, yield, and... 

S. V. (2007) Pd on amine-terminated ferrite nanopartides a complete magnetically recoverable facile catalyst for hydrogenation reactions. Organic Letters, 9 (7), 1419-1421. 

The team of Crooks is involved in the synthesis and the use of dendrimers and, more particularly, poly(amidoamine) dendrimers (PAMAM), for the preparation of dendrimer-encapsulated mono- or bimetallic nanoparticles of various metals (Pt, Pd, Cu, Au, Ag, Ni, etc.) [55, 56]. The dendrimers were used as nanocatalysts for the hydrogenation of allyl alcohol and N-isopropylacrylamide or other alkenes under different reaction conditions (water, organic solvents, biphasic fluorous/or-ganic solvents or supercritical COz). The hydrogenation reaction rate is dependent on dendrimer generation, as higher-generation dendrimers are more sterically... 

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