Enantioselective Friedel-Crafts alkylations catalyzed by bis(oxazolinyl)pyridine-scandium(III) triflate complexes

A series of [beta]-substituted [alpha],[beta]-unsaturated phosphonates and [alpha],[beta]-unsaturated 2-acyl imidazoles are used for the enantioselective Friedel-Crafts addition of a variety of indoles catalyzed by bis(oxazolinyl)pyridine-scandium(III) triflate complexes (Sc(III)-pybox). The nonlinear effects over a range of catalyst concentrations have implicated a mononuclear complex as the active catalyst.