Abstract
This review summarizes palladium-catalyzed carbonylation, transmetalation, and cross-coupling
reactions that lead to carbonylated indoles from indoles and indolyl compounds. Special
attention is drawn to procedures involving the C(sp2 )–H substitution of free (N H)-indoles or (N -substituted)-indoles. Proposed mechanisms are described with, in some cases, personal
comments.
1 Introduction
2 Carbonylative Reactions
2.1 Indolyl Halides as Starting Substrates
2.2 Indolyl Iodides as Intermediates
2.3 Indolylborates as Intermediates
2.4 C(sp2 )–H Reactions
2.4.1 Carboxylation
2.4.2 Carbonylative Alkoxylation
2.4.3 Carbonylative Arylation
2.4.4 Carbonylative Alkenylation
2.4.5 Carbonylative Alkylation
2.4.6 Double Carbonylation
3 Cross-Coupling of Stannyl- or Mercurioindoles
4 Cross-Coupling of Indoles
4.1 Aldehydes
4.2 Alcohols
4.3 α-Diketones
4.4 α-Oxo Esters
4.5 α-Oxocarboxylic Acids
4.6 Nitriles
4.7 Isocyanides
4.8 Isothiocyanates and Isocyanates
4.9 α-Aminocarbonyl Compounds
4.10 Vinyl Ethers or Vinyl Amides
4.11 Toluene and Substituted Toluenes
4.12 Bromodichloromethane
5 Conclusion
Key words acylation - carbonylation - palladium - catalysis - indoles