Regio- and stereoselectivity in long-range asymmetric induction controlledby carbonyliron groups: crystal structures of dicarbonyl-L-[(1,2,3,4,5-eta)-1-R-4-methoxycyclohexadienyl]iron(1+) hexafluorophosphate(1-) [(R = isopropenyl, L = CO), (R=1-styryl, L = CO), (R=1-prop-1-enyl, L = PPh3)] and tricarbonyl[methyl(2,3,4,5-eta)-2-carbomethoxy-2-(4-methoxy-1-(1 '-methylethenyl)cyclohexadien-1-yl)ethanoate]iron(0)

The synthesis of alkenyl-extended cyclohexadienyliron complexes is describe d and reactions are reported demonstrating that regio- and stereoselective funetionalisation can be controlled by the judicious choice of nucleophile, alkali metal counterion and ligand set at iron. The crystal structures of tricarbonyl[(1,2,3,4,5-eta)-1-(1'-methylethenyl)-4-methoxycyclohexadienyl]i ron(1 +) hexafluorophosphate(1 -), tricarbonyl[(1,2,3,4,5-eta)-1-(ethenyl-1 '-phenyl)-4-methoxycyclohexadienyl]iron(1 +) hexafluorophosphate(1-), (E)-d icarbonyl[(1,2,3,4,5-eta)-1-(2'-methylethenyl)-4-methoxycyclohexadienyl]tri phenylphosphineiron(1 +) hexafluorophosphate(1 -), tricarbonyl[methyl(2,3,4 ,5-eta)-2-carbomethoxy-2-(4-methoxy-1-(1'-methylethenyl)cyclohexadien-1-yl) ethanoate]-iron(0), are reported. The stereochemical course of along-range relay of chirality controlled by the carbonyliron group is proven. (C) 2001 Elsevier Science B.V. All rights reserved.