Abstract
This account describes the strategies for the synthesis of functionalized spirooxindole
polycycles, including enantiomerically enriched forms, that we have developed and
reported. The syntheses of these complex molecules were accomplished in a few steps
starting from relatively simple oxindole derivatives and other reactants. Organocatalytic
reactions involved in kinetic resolution or in dynamic kinetic transformation led
to the formation of products with high diastereo- and/or enantioselectivities. Cyclic
1,3-diones, such as 1,3-cyclohexanedione, were used as reactants to provide two reaction
sites for the construction of polycyclic ring systems. To tune the reaction conditions,
2-methyl-1,3-cyclohexanedione was employed. The developed methods enabled the synthesis
of complex functionalized spirooxindole polycycles bearing up to seven stereogenic
centers, and will be useful for the synthesis of potentially bioactive molecules.
1 Introduction
2 Formal (4+1) Cycloaddition and Enantioselective Michael/Henry Cascade Reactions
3 Dynamic Stereoselective Aldol/Oxacyclization Cascade Reactions
4 Dynamic Kinetic Asymmetric Transformation: Diastereo- and Enantioconvergent Michael/Henry
Reactions
5 Dimerization Reactions
6 Conclusion
Key words
asymmetric catalysis - annulation - cycloadditions - enantioselectivity - Michael
addition - organocatalysis
