Coupling of ferrocenyl chromium carbene complex with cyclobutenediones

The coupling of ferrocenyl chromium carbene complex with cyclobutenediones leads to ferrocenyl-substituted 5-alkylidenefuranones and 4-cyclopentene-1,3-diones, methyl ferrocenoate and acetylferrocene in varying amounts. The scope and limitations of these processes are investigated. In comparison with the phenyl analog, ferrocenyl chromium carbene complex has been found to be less reactive. This is also supported by PM3 calculations.