1.3- Cyclohexadienes iron complexes: coupling reactions

Alkenes in (alkene)dicarbonyl(T i-cyclopentadienyl)iron(1 +) cations react with carbon nucleophiles to form new C —C bonds (M. Rosenblum, t974 A. J. Pearson, 1987). Tricarbon-yl(r)5-cyclohexadienyl)iron(l +) cations, prepared from the T 4-l,3-cyclohexadiene complexes by hydride abstraction with tritylium cations, react similarly to give 5-substituted 1,3-cyclo-hexadienes, and neutral tricarbonyl(ti4-l,3-cyclohexadiene)iron complexes can be coupled with olefins by hydrogen transfer at > 140°C. These reactions proceed regio- and stereospecifically in the successive cyanide addition and spirocyclization at an optically pure N-allyl-N-phenyl-1,3-cyclohexadiene-l-carboxamide iron complex (A.J. Pearson, 1989). 

Diene)Fe(GO)3 complexes have been used to construct 2-azaspiro[5.5]undecane and tricyclic ring systems. Intramolecular coupling reactions between diene-Fe(GO)3 complexes and a pendant olefinic group or pendant alcohols have been studied.The cyclization of allylic thioester-functionalized cyclohexadiene iron tricarbonyl... 

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