Iron-Catalyzed C-H Functionalizations under Triazole-Assistance
Matteo Lanzi1, Gianpiero Cera2
1Laboratoire de Chemie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM 25 Rue Becquerel, 67087 Strasbourg, France.
Molecules (Basel, Switzerland)
|April 25, 2020
Summary
Iron catalysts enable C-H bond functionalization in organic synthesis. Triazole directing groups offer a superior, milder alternative to traditional 8-aminoquinoline, enabling novel iron-catalyzed reactions.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- 3d transition metal catalysis, particularly iron, is a key strategy in organic synthesis, offering an alternative to cross-coupling reactions.
- Selective C-H functionalization often requires ortho-directing groups (DGs) to guide the catalyst.
- 8-aminoquinoline (AQ) has been a widely used DG, but limitations exist.
Purpose of the Study:
- To review the recent advancements in iron-catalyzed C-H activation methodologies.
- To highlight the efficacy and advantages of triazole directing groups (DGs) in these reactions.
- To explore the novel reactivities enabled by triazole DGs.
Main Methods:
- Summarizing recent literature on iron-catalyzed C-H functionalization.
- Focusing on the application and properties of triazole directing groups.
- Discussing the synthesis and removal conditions of triazole DGs.
Main Results:
- Triazole DGs are effective alternatives to 8-aminoquinoline (AQ) for iron-catalyzed C-H functionalization.
- Triazoles offer modular synthesis and mild removal conditions.
- Their tunable electronic and geometric properties enable unprecedented reactivities.
Conclusions:
- Triazole DGs represent a significant improvement for iron-catalyzed C-H activation.
- These directing groups facilitate more efficient and versatile synthetic transformations.
- The review highlights the growing importance of triazoles in modern organic synthesis.
More Related Videos
Related Concept Videos
01:26Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism
3.9K
The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl azides. In the Hofmann rearrangement, a primary amide undergoes deprotonation in the presence of a base, followed by halogenation to generate an N-haloamide. A second proton abstraction produces a stabilized anionic species, which rearranges to an isocyanate intermediate via an alkyl group migration from the carbonyl carbon to the neighboring...
3.9K
01:07Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
3.6K
In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.
3.6K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.3K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.3K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
8.8K
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.
8.8K
01:27Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
2.7K
Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).
2.7K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
20.4K
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.
20.4K