The syntheses of two optically active Co(salen)-1,3-butadien-2-yl complexes
are reported. One of the dienyl complexes was characterized by X-ray cryst
allography. The dienyl complexes underwent Diels-Alder reactions with high
enantioselectivity with dimethyl fumarate. A highlight of this chemistry is
that Diels-Alder cycloadduct cobalt complexes were cleanly cleaved at the
cobalt-carbon bond with concomitant optically active cobalt complex startin
g material and optically active cyclohexene cycloadduct recovery.