Related Experiment Video
Updated: May 9, 2026

Optimization of the Ugi Reaction Using Parallel Synthesis and Automated Liquid Handling
Published on: November 11, 2008
Substituent effects in Ugi-smiles reactions
Nicolas Chéron1, Romain Ramozzi, Laurent El Kaïm
1Ecole Normale Supérieure de Lyon, Laboratoire de Chimie, Université de Lyon, UMR 5182, 46 allée d'Italie, F-69364 Lyon Cedex 07, France.
This study details the Ugi-Smiles coupling mechanism by analyzing reactant effects on the energy profile. Carbonyl compounds influence aryl-imidate formation, while amines affect the Smiles rearrangement, providing insights into reaction variations.
Area of Science:
- Organic Chemistry
- Reaction Mechanisms
- Computational Chemistry
Background:
- Ugi-type reactions are versatile multicomponent reactions.
- Previous work elucidated the general Ugi reaction mechanism.
- The Ugi-Smiles coupling presents unique mechanistic questions.
Purpose of the Study:
- To investigate the mechanistic details of the Ugi-Smiles coupling.
- To determine the influence of each reactant on the reaction's energy profile.
- To correlate computational findings with experimental observations.
Main Methods:
- Computational analysis of the reaction's energy profile.
- Systematic variation of each of the four Ugi-Smiles reactants.
- Analysis of intermediate structures and transition states.
Main Results:
- Carbonyl compound variations primarily impact aryl-imidate formation.
- Amine substituents predominantly influence the Smiles rearrangement step.
- Phenol derivative substituents affect both aryl-imidate formation and the rearrangement.
- Isocyanide substituent effects on the energy profile are minimal.
Conclusions:
- The energy profile of the Ugi-Smiles coupling is sensitive to specific reactant modifications.
- Understanding these substituent effects provides a deeper mechanistic insight.
- This detailed analysis aids in predicting and optimizing Ugi-Smiles reaction outcomes.
More Related Videos
08:46Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides
Published on: July 26, 2018
12:22Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction
Published on: February 4, 2013
Related Concept Videos
Predicting Products: Substitution vs. Elimination
The following factors can influence the mechanisms competing against each other:
Predicting Products: SN1 vs. SN2
With increased substitution on the alkyl halide,...
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between the...
SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
SN1 Reaction: Kinetics
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...