title: Metalated nitriles: SNi' cyclizations with a propargylic electrophile.
abstract: A rare 5-exo-dig SNi' cyclization with magnesiated and lithiated nitriles affords acis-fused hydrindane bearing an exocyclic allene. The cyclization of the dilithiated nitrile pits a stereoelectronic preference for atrans-hydrindane against a cyclization through a less strained transition structure to the correspondingcis-hydrindane. Computational modeling suggests that the dilithiated nitrile cyclizes to acis-hydrindane because the preferred transition structure positions the lithium cation in a cone of electron density that bridges the nitrile-bearing carbon, an alkoxide, and an electron-rich alkyne functionality.
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA.
authors.forename: Venkata S
authors.initials: VS
authors.lastname: Pakkala
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Evanseck
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA.
authors.forename: Fraser F
authors.initials: FF
authors.lastname: Fleming
keywords: 5-exo-dig; Hydrindane; Metalated nitriles; SNi′ cyclization