Reaction of organolithium reagents with η5-pentadienyl iron complexes: formation of σ,η3-iron complexes

✍ Scribed by Keith F. McDaniel; Larry R. Kracker II; Parinbam K. Thamburaj

• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 271 KB
• Volume: 31
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)97365-9

✦ Synopsis

Reaction of organolithium reagents with &xuuadienyl iron complex 4 occurs at the WC4 position of the x-system generating s+-iron complexes 5. Air oxidation of these a,+-iron complexes generates cyclohexenones. Reaction of the slightly more electron-poor r$pentadienyl iron complex 11 gives nucleophilic attack at both the CX4 and the Cl/C5 position.

The regioselective reaction of nucleophiles at the terminus of the rc-system of cationic ($-cyclohexadienyl)iron tricarbonyl complexes to pmduce q4-cyclohexadiene iron complexes (Eq. 1, path a. M=Fe(C0)3, n=l) has been intensely studied and utilized in organic synthesis.Q The literature, however, also contains scattered reports of nucleophilic attack at the C2 position of cationic qs-dienyl transition metal complexes, especiahy with acyclic +pentadienyl and +cycloheptadienyl complexes, Nu N d /I I-WJ" .JL c c~)nL.