Enantioselective rhodium-catalyzed allylic substitution with a nitrile anion: construction of acyclic quaternary carbon stereogenic centers.
A direct and highly enantioselective rhodium-catalyzed allylic alkylation of allyl benzoate with α-substituted benzyl nitrile pronucleophiles is described. This simple protocol provides a new approach toward the synthesis of acyclic quaternary carbon stereogenic centers and provides the first example of the direct asymmetric alkylation of a nitrile anion. The synthetic utility of the nitrile products is amply demonstrated through conversion to various functional groups and the synthesis of a bioactive aryl piperazine in an expeditious four-step sequence.
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston K7L 3N6, Canada.
Ben W H
BW
Turnbull
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston K7L 3N6, Canada.
P Andrew
PA
Evans