Regio- and stereoselectivity in long-range asymmetric induction controlled by 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 described 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-methoxycyclohexadieny l]iron(1 +) hexafluorophosphate(1 -), tricarbonyl[(1,2,3,4,5-eta)-1-(ethenyl-1'-phenyl)-4-methoxycyclohexadien yl]iron(1 +) hexafluorophosphate(1-), (E)-dicarbonyl[(1,2,3,4,5-eta)-1-(2'-methylethenyl)-4-methoxycyclohexadi enyl]triphenylphosphineiron(1 +) hexafluorophosphate(1 -), tricarbonyl[methyl(2,3,4,5-eta)-2-carbomethoxy-2-(4-methoxy-1-(1'-methyl ethenyl)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