Metalated nitriles: S_Ni' cyclizations with a propargylic electrophile.

ABSTRACT: A rare 5-exo-dig S_Ni' cyclization with magnesiated and lithiated nitriles affords a cis-fused hydrindane bearing an exocyclic allene. The cyclization of the dilithiated nitrile pits a stereoelectronic preference for a trans-hydrindane against a cyclization through a less strained transition structure to the corresponding cis-hydrindane. Computational modeling suggests that the dilithiated nitrile cyclizes to a cis-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.

SUBMITTER: Lu P 

PROVIDER: S-EPMC4480775 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature