Related Experiment Video
Updated: May 7, 2026
Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
Evolution of a multicomponent system: computational and mechanistic studies on the chemo- and stereoselectivity of a
Salomé Llabrés1, Esther Vicente-García, Sara Preciado
1Department of Physical Chemistry and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Avda Diagonal 643, 08028 Barcelona (Spain), Fax: (+34) 934035987.
Abstract:
The evolution of a ternary molecular system (imine, diene and nitrile) is analyzed to disclose the pathways leading to a divergent synthetic outcome. The Lewis acid catalyzed reaction between cyclohexadiene, 2-phenyl-indol-3-one and acetonitrile yields the imino-Diels-Alder adduct as the major product together with minor amounts of the Mannich-Ritter-amidine product. The experimental and computational data show that the relative orientation of the initial reactants dictates the synthetic outcome. The exo approach between imine and diene leads to the Diels-Alder adduct in a concerted process, whereas the endo mode leads to a polarized intermediate, which is trapped by acetonitrile to yield the multicomponent adduct.
Related Concept Videos
01:17Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:21Chemical Equilibria: Systematic Approach to Equilibrium Calculations
The first step is to identify all the chemical reactions involved, The...
02:05Prochirality
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
02:43E2 Reaction: Stereochemistry and Regiochemistry
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major product and...
02:36Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.