Stabilization of highly reactive cyclic polyolefins by coordination to iron carbonyls: cis-cyclononatetraene-iron tricarbonyl

Abstract

Reaction of cis-bicyclo[6.1.0]nona-2,4,6-triene (C9H10) (I) with Fe2(CO)9, at room temperature, yields a number of complexes (IV)–(IX). One of theśe, (IX), is the Fe2(CO)6 derivative of the starting polyolefin (I), whereas the others are Fe(CO)3 or Fe(CO)4 complexes of isomeric C9H10 polyolefins.(IV) is (h4-l,2,3,4-cis-8,9-dihydroindene)iron tricarbonyl, (V) is tentatively formulated as (h2-or h2-5,6-cis-bicyclo[5.2.0]nona-2,5,8-triene)iron tetracarbonyl, (VI) has been characterized only as C9H10Fe(CO)3, and (VII) and (VIII) are the asymmetric and symmetric isomers (h4-cis-cyclononatetraene)iron tricarbonyl. Characterization of the complexes has been obtained through PMR, IR, and mass spectra.Peculiar features of this reaction are the promotion of the polyolefin (I) rearrangement by iron carbonyls and the stabilization of highly reactive intermediates through coordination to the metal carbonyl groups. fa]Work presented in part at the 3rd International Symposium on Reactivity and Bonding in Transition Organometallic Compounds, Venice, September 9–10, 1970.