Abstract
This Account describes our work on highly electrophilic γ-carbonyl cations featuring propargyldicobalt cations, cycloheptynedicobalt complexes, and the interconnection between the two systems.
1 Introduction
2 γ-Carbonyl Cations via Iron Allyl Cations
3 γ-Carbonyl Cations via Propargyldicobalt Cations
3.1 Synthesis of Velloziolide
3.2 Synthesis of Microstegiol
4 Synthesis of Cycloheptynedicobalt Complexes
4.1 Synthesis via γ-Carbonyl Cations
4.2 Cycloheptynedicobalt Complexes via [4+3] Cycloaddition Reactions
4.3 Cycloheptynedicobalt Complexes via Ring-Closing Metathesis
4.4 Cycloaddition Reactions on Cycloheptynedicobalt Complexes
4.5 Cycloheptynedicobalt Complexes via Intramolecular Nicholas Reactions
5 Dehydrotropylium Ion Co2(CO)6 Complex
6 Final Comments
Key words
carbocation - alkyne complexes - transition-metal - Umpolung - ring closure