Reduction Behavior of Anisyl-substituted P-Ferrocenyl Phospholes

P-Ferrocenylphospholes with differing substituents in alpha-position have been synthesized and their identity and purity was confirmed using multinuclear NMR spectroscopy, MS, elemental analysis and single crystal X-ray diffraction. Furthermore, the redox properties have been explored with electrochemical measurements. Transferring the reduction to a preparative scale using lithium leads to reductive P-C bond cleavage furnishing the corresponding phospholide which has been transformed to P-tert-butyl substituted phosphole. In addition to phospholide formation reductive demethoxylation with transformation of the anisyl substituent to its phenyl analog was observed. For comparison analogous reactions have been explored for the respective P-phenylphospholes which show a different reactivity.

Automated summary

P-Ferrocenylphospholes with different substituents in alpha-position were synthesized and their identity and purity were confirmed using various analytical methods. The redox properties of these compounds were explored using electrochemical measurements. Reduction reactions using lithium resulted in P-C bond cleavage and the formation of corresponding phospholides, which could be further transformed into P-tert-butyl substituted phospholes. Additionally, reductive demethoxylation reactions were observed, leading to the transformation of anisyl substituents to phenyl analogs. Similar reactions were explored for P-phenylphospholes and showed different reactivity.