Related Experiment Video
Updated: Jun 20, 2025
14:07
Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus
Published on: October 3, 2014
13.6K
Ph3PCN2: A stable reagent for carbon-atom transfer.
Taichi Koike1, Jhen-Kuei Yu1, Max M Hansmann1
1Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, 44227 Dortmund, Germany.
Science (New York, N.Y.)
|July 18, 2024
Summary
Chemists developed a stable diazophosphorus ylide for precise single-atom carbon transfer. This novel reagent enables selective synthesis of complex molecules, including pyrazoles, alkynes, and butatrienes.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
Background:
- Precise molecular modification at the single-atom level is a significant challenge in chemistry.
- Developing reagents for chemoselective monoatomic carbon introduction remains a formidable task.
Purpose of the Study:
- To report a straightforward, azide-free synthesis of a novel diazophosphorus ylide.
- To demonstrate the utility of this ylide as a selective carbon transfer reagent.
Main Methods:
- Synthesis of crystalline and isolable diazophosphorus ylide (Ph₃PCN₂).
- Utilizing the ylide as a transfer reagent without additives for various organic transformations.
Main Results:
- The diazophosphorus ylide acts as a highly selective transfer reagent for Ph₃PC and CN₂ fragments.
- Successful synthesis of phosphorus ylide-terminated heterocumulenes and multisubstituted pyrazoles.
- Demonstrated exclusive carbon-atom transfer in reactions with carbonyl compounds, forming vinylidenes for alkynes and butatrienes.
Conclusions:
- The developed diazophosphorus ylide provides an elegant solution for single-atom carbon transfer.
- This reagent offers a versatile platform for synthesizing diverse organic structures with high selectivity.
Related Concept Videos
02:10Carbocations
11.1K
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
11.1K
01:32Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
2.7K
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction...
2.7K
01:18Carboxylic Acids to Acid Chlorides
6.8K
Carboxylic acids react with SOCl2 or PCl5 to form acid chlorides. Amongst the carboxylic acid derivatives, acid chlorides are the most reactive and synthetically important derivatives. They are useful reagents for Friedel–Crafts acylation of some aromatic compounds.
6.8K
01:17Reactions of α-Halocarbonyl Compounds: Nucleophilic Substitution
3.2K
Nucleophilic substitution in α-halocarbonyl compounds can be achieved via an SN2 pathway. The reaction in α-haloketones is generally carried out with less basic nucleophiles. The use of strong basic nucleophiles leads to the generation of α-haloenolate ions, which often participate in other side reactions.
3.2K
02:34Nucleophilic Substitution Reactions
16.3K
Historical perspective
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
16.3K
01:10Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
3.1K
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
3.1K