Dedicated to Professor Herbert Mayr on the occasion of his 70th birthday
Abstract
Iron-catalyzed cross-coupling reactions provide a promising way to form new carbon–carbon bonds and build up molecular complexity. This short review presents recent advances in the synthetic application of these reactions as well as in the elucidation of their mechanism. It also highlights remaining problems and aims at pointing out ways toward possible remedies.
1 Introduction
2 Synthesis: Recent Accomplishments and Unsolved Problems
2.1 Substrate Scope: Electrophiles
2.2 Substrate Scope: Nucleophiles
2.3 Catalyst Activity and Chemoselectivity
2.4 Stereoselectivity
2.5 Practical Aspects
3 Mechanism: Recent Insights and Open Questions
3.1 Transmetallation and Activation of the Iron Precatalyst
3.2 Coupling via Oxidative Addition and Reductive Elimination
3.3 Coupling via C–X Bond Homolysis and Radical Rebound
3.4 Coupling via Bimolecular C–X Bond Homolysis
3.5 Other Reactions of Organoiron Species with Electrophiles
4 Toward Rational Reaction Improvement
5 Conclusion
Key words
catalysis - cross-coupling - iron - organometallic reagents - reaction mechanisms - reactive intermediates
