Application of Asymmetric Catalysis in the <i>E</i> / <i>Z</i> -Stereodivergent Synthesis of Alkenes

Catalytic asymmetric reactions are primarily used to install new stereogenic centers highly enriched in either the <i>R</i> or the <i>S</i> configuration. Here, we demonstrate that chiral catalysts can also be used to control the <i>E</i>/<i>Z</i> geometry of an alkene product devoid of chirality. The process is akin to a parallel kinetic resolution in the sense that a chiral catalyst converts two enantiomers of a starting material to two different products, in this case, only differing in the <i>E</i>/<i>Z</i> geometry of an alkene. The reaction is a reductive addition of a 1,1-dichloroalkene to a chiral secondary allylic alcohol. The catalyst controls the facial selectivity of addition to the allylic alcohol, and a subsequent <i>anti</i>-selective β-hydroxide elimination dictates the <i>E</i>/<i>Z</i> geometry of the alkene product. Synthetic applications of the skipped 1,4-diene products and studies probing the origin of stereoselectivity are described.