The Diels-Alder reaction is one of the most useful synthetic reactions for the construction of the cyclohexane framework. Four contiguous stereogenic centers are created in a single operation, with the relative stereochemistry being defined by the usually endo-favoring transition state. The [4+2]-cycloaddition of a conjugated diene and a dienophile (an alkene or alkyne), an electrocyclic reaction that involves the 4 π-electrons of the diene and 2 π-electrons of the dienophile. The driving force of the reaction is the formation of new σ-bonds, which are energetically more stable than the π-bonds.
Further examples of Diels-Alder reaction promoted by Cinchona Alkaloids can be found in our Buchler Chiral Catalyst Search.
Example from literature
Organocatalytic Asymmetric Inverse-Electron-Demand Diels–Alder Reaction between Alkylidene Pyrazolones and Allyl Ketones: Access to Tetrahydropyrano[2,3-c]pyrazoles. (Bania et al.; J. Org. Chem. 2023, 88, 13, 9584–9593.)