Further solvent-free reactions of ferrocenylaldehydes: Synthesis of 1,1′-ferrocenyldiimines and ferrocenylacrylonitriles

Grinding of 1,1′-ferrocenedicarboxaldehyde with a 2.2 molar equivalent of an aromatic amine in a solvent-free environment provided excellent yields of 1,1′-ferrocenyldiimines. After mixing the aldehyde and amines, a gum or melt formed which eventually solidified to the product. An analytically pure sample of the product was obtained by cold recrystallization. Grinding of ferrocenecarboxaldehyde and 4-substituted phenylacetonitriles under solvent-free conditions provided good yields of the corresponding ferrocenylacrylonitriles. The yield in this reaction was very low when the substituent group para to the acetonitrile group was electron-donating.

Graphical abstractGrinding one equivalent of 1,1′-ferrocenedicarboxaldehyde with 2.2 equivalents of an aniline without solvent provided excellent yields of 1,1′-ferrocenyldiimines. Grinding of ferrocenecarboxaldehyde and 4-substituted phenylacetonitriles under solvent-free conditions provided good yields of the substituted ferrocenylacrylonitriles.Figure optionsDownload full-size imageDownload as PowerPoint slide