8.6: Reduction of Alkenes - Hydrogenation - Chemistry LibreTexts
The examples below show reduction of an alkene, but the ketone and nitrile groups present remain intact and are not reduced. Aromatic rings are also not reduced under the conditions used to reduce alkenes, although these rings appear to contain three carbon-carbon double bonds.
8.6 Reduction of Alkenes: Hydrogenation - OpenStax
Alkenes are much more reactive toward catalytic hydrogenation than most other unsaturated functional groups, and the reaction is therefore quite selective. Other functional groups, such as aldehydes, ketones, esters, and nitriles, often survive alkene hydrogenation conditions unchanged, although reaction with these groups does occur under more ...
12.3: Reduction of Alkenes - Chemistry LibreTexts
First, the alkene must be adsorbed on the surface of the catalyst along with some of the hydrogen. Next, two hydrogens shift from the metal surface to the carbons of the double bond, and the resulting saturated hydrocarbon, which is more weakly adsorbed, leaves the …
19.4. Reduction of alkenes and alkynes | Organic Chemistry II
To convert an alkyne to a cis-alkene, we carry out catalytic hydrogenation reaction using what is known as a ‘Lindlar catalyst” – finely powdered palladium deposited on calcium carbonate and modified with lead salts and quinoline. This is essentially a less reactive version of the normal transition metal catalyst used in hydrogenation of ...
19.4: Reduction of alkenes and alkynes - Chemistry LibreTexts
To convert an alkyne to a cis-alkene, we carry out catalytic hydrogenation reaction using what is known as a ‘Lindlar catalyst” – finely powdered palladium deposited on calcium carbonate and modified with lead salts and quinoline. This is essentially a less reactive version of the normal transition metal catalyst used in hydrogenation of ...
Lithium borohydride is commonly used for the selective reduction of esters and lactones to the corresponding alcohols in the presence of carboxylic acids, tertiary amides, and nitriles. Aldehydes, ketones, epoxides, and several other functional …
Reduction of Alkenes: Hydrogenation | MCC Organic Chemistry
describe the mechanism of the catalytic hydrogenation of alkenes. explain the difference between a heterogeneous reaction and a homogeneous reaction. recognize that other types of compounds containing multiple bonds, such as ketones, esters, nitriles and aromatic compounds, do not react with hydrogen under the conditions used to hydrogenate ...
Silane- and peroxide-free hydrogen atom transfer hydrogenation …
2021年2月11日 · Hydrogen atom transfer (HAT) hydrogenation of alkenes usually requires stoichiometric silanes and peroxides. Here, the authors report a silane- and peroxide-free HAT hydrogenation method using a...
8.6 Reduction of Alkenes: Hydrogenation - Fiveable
2024年5月7日 · Horiuti-Polanyi Mechanism: The Horiuti-Polanyi mechanism is a model that describes the step-by-step process of the catalytic hydrogenation of alkenes. It provides a detailed explanation of how hydrogen gas interacts with an alkene substrate in the presence of a metal catalyst to reduce the carbon-carbon double bond.
Reduction of Alkenes: Catalytic Hydrogenation - JoVE
Hydrogenation of alkenes is a reduction process wherein the addition of molecular hydrogen breaks the weak π bond of an alkene to form two C–H σ bonds of an alkane. Intrinsically, hydrogenation of alkenes has a large energy barrier, making …
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