Abstract
Palladium-mediated cyclization reactions have been recognized
as some of the simplest and useful tools for regio- as well as stereoselective
syntheses of carbo- and heterocyclic compounds. In the multi-step
syntheses of natural products it is frequently used as one of the
most important steps. In this review article, we have summarized
the various ways of constructing five- and six-membered heterocyclic
rings by palladium-catalyzed intramolecular cyclizations published
between 2008 and 2010.
1 Introduction
2 Synthesis of Heterocycles via Alkene Cyclizations
2.1 Intramolecular Heck Cyclizations of Vinylic Halides
2.2 Intramolecular Heck Cyclizations of Aryl Halides
2.3 Intramolecular Heck Reactions of Aryl Triflates
2.4 Intramolecular Hydroxylations of Alkenes
2.5 Intramolecular Aminations of Alkenes
2.6 Intramolecular Annulations of Alkenes via Double C-H Activations
2.7 Intermolecular Annulations of Alkenes
3 Synthesis of Heterocycles via Alkyne Cyclizations
3.1 Intramolecular Cyclizations of Internal Alkynes
3.2 Intramolecular Cyclizations of Terminal Alkynes
3.3 Intermolecular Annulations of Alkynes
4 Synthesis of Heterocycles via Allene Cyclizations
5 Intramolecular Biaryl-Coupling Reactions
6.1 Biaryl Couplings via C-X Functionalizations
6.2 Biaryl Couplings via Double C-H Activations
6 Heterocycles via Carbonylative Cyclizations
7 Synthesis of Heterocycles from Alkane Substrates
8 Miscellaneous
9 Conclusion
Key words
palladium catalysis - fused heterocycles - C-H
activation - C-C coupling - regioselectivity - stereoselectivity
