Photoredox-Catalyzed Decarboxylative Nitro-Mannich Reaction.
Deshkanwar Singh Brar1, Jon A Tunge1
1Department of Chemistry, The University of Kansas, 1567 Irving Rd., Lawrence, Kansas 66045, United States.
Organic Letters
|July 11, 2025
Summary
We developed a new method for synthesizing beta-nitroamines using photoredox catalysis and gem-bromonitroalkanes. This decarboxylative nitro-Mannich reaction offers a simple way to create diverse molecules under mild conditions.
Area of Science:
- Organic Chemistry
- Synthetic Methodology
- Photocatalysis
Background:
- Beta-nitroamines are important synthetic targets with adjacent nitrogen atoms in different oxidation states.
- Existing methods for synthesizing beta-nitroamines can be complex or require harsh conditions.
Purpose of the Study:
- To develop a novel, efficient, and mild method for synthesizing beta-nitroamines.
- To explore the synthesis of substituted beta-amino esters.
- To investigate the reaction mechanism and enable transition metal-free C(sp3)-C(sp3) bond formation.
Main Methods:
- Photoredox catalysis
- Decarboxylative nitro-Mannich reaction
- Utilizing gem-bromonitroalkanes and carboxylic acids
Main Results:
- Successfully synthesized skeletally diverse beta-nitroamines.
- Achieved synthesis of substituted beta-amino esters.
- Demonstrated an operationally simple protocol under mild conditions.
- Mechanistic studies indicated radical decarboxylation, halogen-atom transfer, and reductive radical-polar crossover.
Conclusions:
- The developed protocol provides a facile route to beta-nitroamines and beta-amino esters.
- The reaction proceeds via a unique mechanism involving radical intermediates and umpolung.
- This method obviates the need for carboxylic acid preactivation and transition metal catalysts.
More Related Videos
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
Related Concept Videos
01:19Nitrosation of Enols
3.9K
The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.
3.9K
00:57Nitriles to Ketones: Grignard Reaction
4.8K
Organomagnesium halides, commonly known as Grignard reagents, convert nitriles to ketones and proceed through a nucleophilic acyl substitution. Nitriles react with a Grignard reagent, followed by an aqueous acid, to yield ketones. The reaction introduces a new carbon–carbon bond. The alkyl–magnesium bond in the Grignard reagent is highly polar, so the alkyl carbon develops a carbanionic character and acts as a nucleophile.
The mechanism begins with a nucleophilic attack by the Grignard...
The mechanism begins with a nucleophilic attack by the Grignard...
4.8K
01:20Electrophilic Aromatic Substitution: Nitration of Benzene
6.5K
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
6.5K
01:202° Amines to N-Nitrosamines: Reaction with NaNO2
4.6K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.6K
01:25Nonenolizable Aldehydes to Acids and Alcohols: The Cannizzaro Reaction
2.1K
The Cannizzaro reaction is a base-promoted redox reaction producing a primary alcohol and a carboxylic acid from two molecules of a nonenolizable aldehyde. The reaction commences when the anionic counterpart of the base attacks the carbonyl carbon, resulting in a tetrahedral alkoxide intermediate. The base then abstracts a proton from the intermediate to generate an unstable dianionic species. This intermediate enables the release of the aldehydic hydrogen as a hydride ion. An intermolecular...
2.1K
01:19Preparation of Carboxylic Acids: Hydrolysis of Nitriles
4.7K
Nitriles (R–CN) can be converted into carboxylic acids (R–COOH) upon treatment with aqueous acids, i.e., upon hydrolysis of nitriles. Under base-catalyzed conditions, carboxylate anions (R–COO−) are formed.
4.7K