Cobalt fluorocarbenes: Cycloaddition reactions with tetrafluoroethylene and reactivity of the perfluorometallacyclic products

Abstract

Cobalt fluorocarbene complexes CpCo(î - "CFRF) (PPh2Me) (Cp = η5-C5H5, R F = F or CF3) react with tetrafluoroethylene to give the metallacyclobutanes CpCo(κ2-CFRFCF 2CF2-)(PPh2Me) in the first examples of cycloaddition reactions between perfluoroalkenes and metal perfluorocarbenes. The metallacyclic products undergo a variety of reactions upon activation of the C-F bonds, including Brønsted acid-catalyzed C-F/Co-C scrambling. Implications for metal-catalyzed metathesis and polymerization of perfluoroalkenes are discussed. © 2013 American Chemical Society.