posted on 2015-12-17, 05:45authored byWenyong Chen, Ming Chen, John F. Hartwig
We
report asymmetric allylic alkylation of barium enolates of cyclic
ketones catalyzed by a metallacyclic iridium complex containing
a phosphoramidite ligand derived from (R)-1-(2-naphthyl)ethylamine.
The reaction products contain adjacent quaternary and tertiary stereocenters.
This process demonstrates that unstabilized cyclic ketone enolates
can undergo diastereo- and enantioselective Ir-catalyzed allylic
substitution reactions with the proper choice of enolate countercation.
The products of these reactions can be conveniently transformed to
various useful polycarbocyclic structures.