Abstract
This review highlights the advances in the literature up to May
2009 in the synthesis of spirocyclic indoline natural products. The
focus is on formation of the spirocyclic chiral center, including both
enantioselective and diastereoselective methods. This review is
split into two main sections, the first consisting of the formation of
spirooxindoles and their application towards oxindole alkaloids, and
the second covering asymmetric synthesis of spiroindoline natural
products.
1 Introduction
2 Spirooxindole Alkaloids
2.1 Oxidative Rearrangements
2.2 Azomethine Ylide Cycloaddition
2.3 Asymmetric Addition-Elimination
2.4 Palladium-Catalyzed Heck Reactions
2.5 Palladium-Catalyzed Allylic Alkylation
2.6 Ring Expansion
2.7 Mannich Reaction
3 Spiroindoline Alkaloids
3.1 Palladium Catalyzed Asymmetric Allylic Alkylation
3.2 [4+2] Cycloaddition
3.3 Oxidative Rearrangement
3.4 Diastereoselective Pummerer Rearrangement
3.5 Tandem Iminium Cascade
3.6 Fischer Indole Synthesis
3.6.1 Diastereoselective Ring-Closing Metathesis
3.6.2 Diastereoselective Alkylation of Chiral Lactams
3.6.3 Regioselective Schmidt Reaction
3.6.4 Diastereoselective Ketene Lactonization
3.6.5 Harley-Mason Reaction
3.6.6 SN 2-Type Indole Alkylation
3.6.7 Aza-Cope-Mannich Rearrangement
4 Conclusion
Key words
alkaloids - spiro compounds - indoles - asymmetric
synthesis - natural products
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