Reactivity patterns in cationic tricarbonyliron complexes: crystallographic proof of stereoselectivity in long range asymmetric induction in the 1,3/1′,2′ series

The analysis of patterns of regioselectivity in cyclohexadienyl complexes illustrates the versatility and power of the iron-based methodology in reaction sequences that make multiple use of the metal to establish a series of chiral centres. The conversion of tricarbonyl(η 4 -cyclohexadienone)iron(0) into the dimethyl malonate adduct 4, which contains two chiral centres at carbon besides the controlling chirality of the tricarbonyliron complex itself, provides an example of long-range asymmetric induction. The relative stereochemistry of the 1,3/1',2' product has been defined as S,S,R * ,R * .