The catalyst stabilizes the exo transition state by strategic binding of zinc ( II ) ion to pyridine nitrogen atoms on the diene and dienophile.
22.
In the following example, the methyl group on the dienophile forced the molecule to adopt that specific 6-membered ring conformation on the molecule.
23.
It can also be reacted with sulfur tetrafluoride to produce hexafluoro-2-butyne, a powerful dienophile for use in Diels-Alder reactions.
24.
As such, the molecule is highly electrophilic, and is widely employed as a dienophile in cycloaddition reactions, such as the Diels-Alder reaction.
25.
The addition of a CLA selectively activates one component of the reaction ( the diene or dienophile ) while providing a stereodefined environment that permits unique enantioselectivity.
26.
The addition of CALB catalyzes the reaction between the ( R ) isomer and the ester reagent to form a product with a diene and a dienophile.
27.
Dicyanoacetylene is a powerful dienophile because the cyanide groups are aromatic compound durene ( 1, 2, 4, 5-tetramethylbenzene ) to form a substituted bicyclooctatriene.
28.
For example, in the palladium-catalyzed enantioselective Diels-Alder reaction shown below, the dienophile is thought to coordinate the metal center at the equatorial sites.
29.
The dienophile, the activated alkene, can often be attached to electron-donating alkyl groups on target molecules, thus making the dienophile more suitable for the reaction.
30.
The dienophile, the activated alkene, can often be attached to electron-donating alkyl groups on target molecules, thus making the dienophile more suitable for the reaction.
