New Dimensions in Indole Chemistry: From Ligand Design to Natural Products

Specially-activated indoles provide a versatile entry into new ligand systems, especially those based on 2,2′-bi-indolyl and 2,2′-di-indolylmethane building blocks. Their reactions with aldehydes and ketones generate new structures related to important natural products. Cyclisation reactions between N1 and C2 give pyrrolo[a]indole derivatives, whilst a wider range of cyclisations between N1 and C7 give rise to pyrroloquinoline and pyrrolophenanthridone derivatives. 1. Introduction 2. Indoles as Ligand Building Blocks 3. 2,2′-Bi-indolyl Ligand Systems 4. 2,2′-Di-indolylmethane Ligand Systems 5. Reactions of Indoles with Aldehydes 6. Reactions of Indoles with Methyl Ketones 7. Indole-based Intramolecular Nitrone Cycloadditions 8. Pyrroloquinoline Derivatives 9. Pyrrolophenanthridone Derivatives 10. Summary and Outlook