Related Experiment Video
Updated: Nov 6, 2025
06:26
Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source
Published on: August 17, 2018
10.2K
Radical Carboxylative Cyclizations and Carboxylations with CO2
Jian-Heng Ye1, Tao Ju1, He Huang1
1Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
Accounts of Chemical Research
|May 6, 2021
Summary
Researchers developed novel methods for utilizing carbon dioxide (CO2) in organic synthesis, employing radical chemistry and visible-light photoredox catalysis. These advancements enable efficient synthesis of valuable compounds, including carboxylic acids and diacids, from CO2 under mild conditions.
Area of Science:
- Organic Synthesis
- Green Chemistry
- Radical Chemistry
- Photocatalysis
Background:
- Carbon dioxide (CO2) is an abundant, inexpensive, and renewable C1 building block, but its inertness poses challenges for utilization.
- Existing CO2 utilization methods have limitations in substrate scope, reaction systems, and activation strategies.
- Radical chemistry offers vast possibilities but requires control over reactivity and selectivity.
Purpose of the Study:
- To develop highly useful CO2 transformations involving radicals, balancing reactivity and selectivity under mild conditions.
- To explore visible-light photoredox catalysis and single-electron activation strategies for CO2 utilization.
- To synthesize valuable organic compounds, including carboxylic acids and diacids, from CO2.
Main Methods:
- Cu-catalyzed radical-type oxytrifluoromethylation of amines.
- Visible-light photoredox catalysis for carboxylative cyclization and carboxylation.
- Single-electron transfer (SSET) reduction for selective umpolung carboxylations and dearomative arylcarboxylation.
- Visible-light-driven thiocarboxylation and hydrocarboxylation using catalytic iron salts or organocatalysts.
Main Results:
- Developed Cu-catalyzed and visible-light-promoted carboxylative cyclizations yielding 2-oxazolidones.
- Achieved selective umpolung carboxylations and dearomative arylcarboxylation of indoles using CO2.
- Reported visible-light-driven dicarboxylation of alkenes, allenes, and (hetero)arenes, incorporating two CO2 molecules.
- Demonstrated visible-light-driven thiocarboxylation and hydrocarboxylation of alkenes with CO2 via single-electron activation.
Conclusions:
- Established efficient and selective radical-type transformations of CO2 under mild conditions.
- Visible-light photoredox catalysis and single-electron activation are powerful strategies for CO2 utilization.
- Developed new pathways for synthesizing valuable carboxylic acids, diacids, and other organic compounds from CO2.
Related Concept Videos
00:47Radical Formation: Addition
2.0K
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
2.0K
01:11Radical Reactivity: Overview
2.3K
Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired...
2.3K
01:33Radical Reactivity: Intramolecular vs Intermolecular
1.9K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
1.9K
01:41Reactions of Carboxylic Acids: Introduction
3.5K
Carboxylic acids possess an acidic –COOH functional group. The acidity can be attributed to the resonance stabilization of their conjugate base, wherein the negative charge is delocalized over both oxygen atoms.
3.5K
00:51Radical Formation: Elimination
2.0K
Another method of radical formation is the elimination process. It is the opposite of the addition route and is driven by the instability of the radical. For example, as depicted in Figure 1, dibenzoyl peroxide yields a pair of unstable radicals upon homolysis. Given its instability, this radical spontaneously undergoes elimination via a C–C bond cleavage to form a relatively more stable phenyl radical. The mechanism involves cleavage of the bond between the α and β positions with respect...
2.0K
01:02Loss of Carboxy Group as CO2: Decarboxylation of β-Ketoacids
3.5K
Carboxylic acids, upon heating, undergo a decarboxylation reaction by releasing carbon dioxide gas. Monocarboxylic acids do not undergo decarboxylation easily. However, a silver salt of carboxylic acid reacts with bromine or iodine under high temperature to release carbon dioxide gas and forms halide with one less carbon. This reaction is called the Hunsdiecker reaction.
3.5K