関連する実験動画

Updated: May 30, 2026

Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
09:37

Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry

Published on: October 18, 2019

H2/CO混合物によるニオビウム (III) イミド複合体によるZ選択的,触媒的内部アルキン半水素化

Thomas L Gianetti1, Neil C Tomson, John Arnold

  • 1Department of Chemistry, University of California, Berkeley, California 94720, United States.

Journal of the American Chemical Society
|August 23, 2011
PubMed
まとめ

この研究では,内部アルキンのニオビウム ((III) 触媒による新種の水素化が (Z) -アルケンに変換されたと報告されています. この前例のないメカニズムは,ニオビウム (((V) メタラサイクロプロペンの中間物質と,H (((2) との σ-結合メタテシスを含む.

さらに関連する動画

A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones07:30

A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones

Published on: January 21, 2020

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production08:40

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production

Published on: December 6, 2021

関連する概念動画

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation02:24

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation02:47

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation

Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation02:17

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Regioselectivity and Stereochemistry of Hydroboration02:36

Regioselectivity and Stereochemistry of Hydroboration

A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Reduction of Alkenes: Catalytic Hydrogenation02:13

Reduction of Alkenes: Catalytic Hydrogenation

Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide02:44

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.