Reaktive τ-komplexe der elektronenreichen übergangsmetalle: VI. Katalytische und stöchiometrische reaktionen von τ-aren-eisenkomplexen mit alkinen

Abstract The reactive τ-arene complexes bis(ethene)toluene)iron, (toluene)(1-methylnaphthalene)iron, and bis(tolueneiron)cyclooctatetraene are catalysts for the cyclotrimerization of alkynes RCCR′ (R,R′ = H, CH 3 , C 2 H 5 , t-C 4 H 9 , C 6 H 5 , COOCH 3 ) to benzene derivatives. When R = R′ = Si(CH 3 ) 3 , CH 2 OH or COOH the reaction fails. In the case of bis(ethene)(toluene)iron and acetylenedicarbonic acid dimethylester a [2 + 2 + 2]cycloaddition of two alkynes and one ethene takes place. When the primary products of the catalytic reaction were trapped with trialkylphosphite, complexes of the type tris(trialkylphosphite)(alkynene)iron and tris[bis(trimethylsilyl)acetylene]bis(trimethylphosphite)diiron, become readily accessible.