Related Experiment Video
Updated: Jun 20, 2025
12:07
Microwave-assisted Intramolecular Dehydrogenative Diels-Alder Reactions for the Synthesis of Functionalized Naphthalenes/Solvatochromic Dyes
Published on: April 1, 2013
17.1K
Extra-Annulated Chlorophyll Derivatives by Scholl Reaction
Takuma Imuta1, Nobuyuki Hara1, Shin Ogasawara1
1Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Organic Letters
|July 17, 2024
Summary
Researchers synthesized a novel chlorophyll derivative with a unique fused ring structure, leading to molecular helicity. This discovery offers new insights into complex organic molecule synthesis and properties.
Area of Science:
- Organic Chemistry
- Photochemistry
- Spectroscopy
Background:
- Chlorophyll derivatives are crucial in photosynthesis and photodynamic therapy.
- Scholl reactions are important for synthesizing polycyclic aromatic hydrocarbons.
- Developing new synthetic routes for complex macrocycles is an ongoing challenge.
Purpose of the Study:
- To synthesize a novel, extra-annulated chlorophyll derivative.
- To investigate the induction of molecular helicity in chlorophyll structures.
- To characterize the photophysical properties of the new compound.
Main Methods:
- Ferric chloride assisted Scholl reaction of methyl (3,5-dimethoxyphenyl)carbonyl-pyropheophorbide-a.
- Separation of stereoisomers by recrystallization.
- Confirmation of stereochemistry using circular dichroism (CD) spectra.
Main Results:
- An extra-annulated, didehydrogenated chlorophyll derivative was successfully synthesized.
- The compound exhibited induced molecular helicity due to steric interactions.
- Separated P/M-stereoisomers showed distinct CD spectra.
- Distorted chlorin π-systems resulted in broad electronic absorption bands across visible and near-infrared regions.
Conclusions:
- The Scholl reaction provides a viable route to helically cyclized chlorophyll derivatives.
- Steric factors play a significant role in inducing helicity in these systems.
- The unique photophysical properties suggest potential applications in materials science or photochemistry.
More Related Videos
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Related Concept Videos
02:26Preparation and Reactions of Sulfides
4.8K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
4.8K
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
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
1.9K
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...
1.9K
01:27Radical Substitution: Halogenation of Alkanes and Alkyl Substituents
8.0K
In the presence of heat or light, alkanes react with molecular halogens to form alkyl halides by a substitution reaction called radical halogenation. This reaction has three steps: initiation, propagation, and termination, as seen in the radical chlorination of methane to produce methyl chloride.
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
8.0K
01:38Preparation of Alcohols via Substitution Reactions
5.8K
Overview
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
5.8K
01:14α-Halogenation of Carboxylic Acid Derivatives: Overview
3.3K
Unlike aldehydes and ketones, carboxylic acids do not readily participate in α halogenation reactions via enols or enolate intermediates. However, α-halogenated acids are obtained through other methods. One of the approaches is the Hell–Volhard–Zelinsky (HVZ) reaction, wherein the carboxylic acid is treated with halogen in the presence of PBr3. It involves the conversion of acid to acid halide, which exists in equilibrium with its enol form. The enol attacks the...
3.3K