title: Alkene-directed, nickel-catalyzed alkyne coupling reactions.
abstract: In alkene-directed, nickel-catalyzed coupling reactions of 1,3-enynes with aldehydes and epoxides, the conjugated alkene dramatically enhances reactivity and uniformly directs regioselectivity, independent of the nature of the other alkyne substituent (aryl, alkyl (1 degrees , 2 degrees , 3 degrees )) or the degree of alkene substitution (mono-, di-, tri-, and tetrasubstituted). These observations are best explained by a temporary interaction between the alkene and the transition metal center during the regioselectivity-determining step. The highly substituted 1,3-diene products are useful in organic synthesis and, in conjunction with a Rh-catalyzed, site-selective hydrogenation, afford allylic and homoallylic alcohols that previously could not be prepared in high regioselectivity (or at all) with related Ni-catalyzed alkyne coupling reactions.
authors.affiliation: Massachusetts Institute of Technology, Department of Chemistry, Cambridge, Massachusetts, USA.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Miller
authors.forename: Torsak
authors.initials: T
authors.lastname: Luanphaisarnnont
authors.forename: Carmela
authors.initials: C
authors.lastname: Molinaro
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Jamison