Intramolecular Reactions
Intramolecular Reactions - Related Videos
01:18
Intramolecular Aldol Reaction
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2025
Intramolecular aldol reaction occurs in dicarbonyl compounds such as dialdehydes, diketones, and keto-aldehydes. The dicarbonyl compounds possess more than one nucleophilic ⍺ carbon for the base to deprotonate and form the enolates. For example, in symmetrical diketones, there are four ⍺ carbons. Hence, four types of enolates are possible when treated with a base. However, since the molecule is symmetrical, the enolates formed on either side of one carbonyl group are equivalent to those formed...
03:00
Intermolecular vs Intramolecular Forces
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2020
Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular force is influenced by the distance of separation between molecules. The forces significantly affect the interactions in solids and liquids, where the molecules are close together. In gases, IMFs become important only under high-pressure conditions (due to the proximity of gas molecules). Intermolecular forces dictate the physical properties of...
12:07
Microwave-assisted Intramolecular Dehydrogenative Diels-Alder Reactions for the Synthesis of Functionalized Naphthalenes/Solvatochromic Dyes
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Cited by 2 •
2013
Microwave-assisted intramolecular dehydrogenative Diels-Alder (DA) reactions provide concise access to functionalized cyclopenta[b]naphthalene building blocks. The utility of this methodology is demonstrated by one-step conversion of the dehydrogenative DA cycloadducts into novel solvatochromic fluorescent dyes via Buchwald-Hartwig palladium-catalyzed cross-coupling reactions.
01:33
Radical Reactivity: Intramolecular vs Intermolecular
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2023
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 carbon–halogen...
01:13
Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization
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2023
Dieckmann cyclization is an intramolecular Claisen condensation of diesters. The reaction occurs in the presence of a base and generates a cyclic β-ketoester as the final product. Commonly, 1, 6 and 1, 7-diesters are preferred substrates for the reaction since the generated five, and six-membered cyclic β-keto esters are particularly more stable. In the reaction, α carbon connected to one end of the ester ends serves as an enolate nucleophile after losing its proton to the base. The carbonyl...
FAQs
A tether can bring reactive groups into closer proximity, increasing their effective concentration relative to separated molecules. This advantage does not guarantee reaction, because the linked groups must also adopt a suitable geometry and orbital alignment. When these requirements are met, the reaction may favor selective bond formation within one molecule instead of competing pathways involving other molecules.
Tether length affects whether reactive groups can reach a productive arrangement and what ring size forms after cyclization. The resulting ring may also experience strain, which can influence the feasibility and outcome of the transformation. Considering both factors helps chemists distinguish a promising molecular design from one that places the reacting groups too far apart or creates an unfavorable framework.
Proximity alone is insufficient for successful bond formation. The reacting groups must approach with a geometry that allows the relevant orbitals to overlap appropriately, while the reaction conditions must support that arrangement. These requirements help explain why structurally similar substrates can behave differently and why controlling molecular shape is central to predicting cyclization, rearrangement, or substitution outcomes.
Although tethering favors reaction within a single molecule, reactive groups may still participate in intermolecular processes involving separate molecules. Such competition can reduce selectivity or alter the products obtained. Evaluating the balance between intramolecular proximity and intermolecular reactivity is therefore important when interpreting results and choosing conditions intended to promote the desired molecular transformation.
A useful design begins by identifying the reactive groups, examining the tether that connects them, and estimating whether it permits productive geometry. Chemists then consider potential ring strain, orbital alignment, and conditions that promote the intended transformation. Finally, they assess possible intermolecular competition, allowing the proposed reaction to be judged by both feasibility and selectivity.
These reactions are particularly valuable when a synthesis requires construction of a ring or a more complex molecular framework. Linking reactive groups within one substrate can help control which bonds form and may support selective assembly of natural-product-like structures. Their use is therefore relevant to synthetic routes where connectivity and stereochemistry must be managed rather than left to competing pathways.
The observed framework, connectivity, and stereochemistry can help chemists evaluate whether the proposed transformation occurred through the intended intramolecular pathway. Product patterns may also reveal the influence of tether length, ring strain, geometry, or competing intermolecular reactions. Interpreting these features connects the isolated outcome with the molecular design and conditions used in the experiment.
By forming bonds between functional groups already connected in one molecule, these transformations can generate rings and build larger molecular frameworks in a controlled sequence. That capability is useful for assembling complex, natural-product-like structures while tracking connectivity and stereochemistry. In route design, the reaction can serve as a strategic step that organizes several structural features within one transformation.