Abstract
In this article, the stereoselectivity of metal-catalyzed cyclizations of 1,6-dienes is examined according to the elementary steps which can be envisaged as triggers of the rearrangements. Crucial results have been obtained which demonstrate that enantioselective and diastereoselective cyclizations are possible. However, a lack of stereoselectivity is often observed for 1,6-dienes having a prochiral tether, which appears to originate in the lack of differentiation between the two olefins of the substrates.
1 Introduction
2 Oxidative Cyclometalation
3 Copper-Catalyzed Photocycloaddition
4 Intermolecular Hydrometalation
5 Carbometalation and Sila-Metalation
6 π-Allyl Formation in Metallo-Ene Cyclization
7 Olefin Electrophilic Activation
8 C–H Activation
9 Conclusion
Key words
cyclization - metal catalysis - 1,6-dienes - stereoselectivity - C–H activation