Studies on ferrocene derivatives. Part 12. Substituent effects for the disproportionation, synproportionation and ligand exchange reactions oft-butylferrocenes

✍ Scribed by Takatoshi Hayashi; Yutaka Okada; Satoshi Shimizu

• Book ID: 104638761
• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 336 KB
• Volume: 21
• Category: Article
• ISSN: 0340-4285
• DOI: 10.1007/bf00140783

✦ Synopsis

The disproportionations and synproportionations of tbutylferrocenes and the ligand exchanges between the ferrocenes and benzene have been studied. The steric effects of the t-butyl groups were found to significantly affect the ratio of the products obtained. In these reactions, aluminium chloride attacks and abstracts the cyclopentadienyl ring. As a result, the ferrocene molecule decomposes into two fragments. The aluminium chloride selectively attacks the least sterically hindered cyclopentadienyl ring. The steric effect for a cyclopentadienyl ring bearing two t-butyl groups is substantial and inhibits attack by aluminium chloride. The product therefore contains the cyclopentadienyl ring which has the higher steric hindrance (i.e. the 1,3-di-substituted cyclopentadienyl ring).