Direct one step preparation and 13C-NMR spectroscopic characterization of a-ferrocenyl carbocations derived from ferrocene and carbonyl compounds in trifluoroacetic acid medium1a

• Main Authors: Prakash G.K. Surya, Buchholz Herwig A., Vaughan Julian F.S., Wang Qi, Olah George. A.
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 1999-01-01
• Series: Journal of the Brazilian Chemical Society
• Subjects: ferrocene; alpha-ferrocenyl carbocations; 13C-NMR of alpha-ferrocenylalkyl carbocations
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000400010
• ISSN: 0103-5053

Reaction of aldehydes and ketones with ferrocene, in the presence of trifluoroacetic acid, afforded a series of stable long lived alpha-ferrocenylalkyl carbocations which were characterized by 13C-NMR spectroscopy. When this reaction was attempted using tetraphenylcyclopentadienone, quite unexpectedly the corresponding dihydro derivative 3 was isolated, in very good yield. Formation of this compound may require ferrocene acting as a reducing agent.