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Updated: Jun 18, 2026
10:44
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
The trichloromethide and bromodichloromethide carbanions
Robert A Moss1, Min Zhang, Karsten Krogh-Jespersen
1Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, USA. moss@rutchem.rutgers.edu
Organic Letters
|November 20, 2009
Summary
Photochemically generated dichlorocarbene reacts with halide ions to form carbanion intermediates. These findings shed light on the mechanisms of dichlorocarbene generation from haloforms.
Area of Science:
- Organic Chemistry
- Photochemistry
- Reaction Mechanisms
Background:
- Dichlorocarbene is a key reactive intermediate in organic synthesis.
- Classical methods for generating dichlorocarbene from haloforms involve base catalysis.
- The precise mechanisms of these reactions, particularly the role of intermediate species, require further elucidation.
Purpose of the Study:
- To investigate the reaction pathways of photochemically generated dichlorocarbene.
- To identify the carbanion intermediates formed during these reactions.
- To compare photochemical generation with classical base-catalyzed methods.
Main Methods:
- Photochemical generation of dichlorocarbene using UV irradiation.
- Reaction of dichlorocarbene with chloride and bromide ions in solution.
- Spectroscopic and kinetic analysis to characterize reaction intermediates.
Main Results:
- Photochemically generated dichlorocarbene reacts with chloride ions to form trichloromethide carbanions.
- Reaction with bromide ions yields bromodichloromethide carbanions.
- These carbanions are identified as central intermediates, analogous to those in base-catalyzed haloform reactions.
Conclusions:
- Photochemical generation provides an alternative route to dichlorocarbene.
- The study confirms the identity of key carbanion intermediates in dichlorocarbene chemistry.
- This work offers insights into the fundamental mechanisms of haloform reactions.
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