Related Experiment Video
Updated: Nov 2, 2025
07:06
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
8.3K
Iridium-Catalyzed Hydroarylation via C-H Bond Activation
1Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi, Osaka, 558-8585, Japan.
Chemical Record (New York, N.Y.)
|June 8, 2021
Summary
Iridium catalysts enable efficient synthesis of substituted arenes through C-H activation hydroarylation, offering an alternative to classical methods. This review details recent studies on various substrates and asymmetric reactions.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Classical Friedel-Crafts reactions for arene synthesis have limitations.
- C-H activation offers a more efficient and versatile approach.
- Hydroarylation is a key strategy for constructing substituted arenes.
Purpose of the Study:
- To review recent advancements in iridium-catalyzed hydroarylation reactions.
- To explore the application of these methods to diverse substrates.
- To highlight the development of asymmetric hydroarylation techniques.
Main Methods:
- Utilized cationic and hydroxoiridium complexes as catalysts.
- Employed ligands such as 1,5-cyclooctadiene (cod) and chiral dienes.
- Investigated intermolecular hydroarylation of vinyl ethers, alkynes, and dienes, and intramolecular hydroarylation of ketones.
Main Results:
- Achieved efficient iridium-catalyzed intermolecular hydroarylation of various unsaturated substrates.
- Demonstrated successful intramolecular hydroarylation of m-allyloxyphenyl ketones, including asymmetric variants.
- Identified specific iridium catalysts and ligands that control reactivity and selectivity.
Conclusions:
- Iridium-catalyzed hydroarylation via C-H activation is a powerful synthetic tool.
- The choice of catalyst and ligand is crucial for substrate-dependent efficiency and selectivity.
- The methodology provides a valuable alternative to traditional arene synthesis routes.
More Related Videos
Related Concept Videos
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
8.3K
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.
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.
8.3K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.6K
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...
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...
3.6K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
19.4K
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.
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.
19.4K
02:13Reduction of Alkenes: Catalytic Hydrogenation
12.9K
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...
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...
12.9K
02:36Regioselectivity and Stereochemistry of Hydroboration
8.7K
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.
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.
8.7K
03:08Hydroboration-Oxidation of Alkenes
9.6K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
9.6K