Enantioselective Friedel-Crafts alkylation reactions catalyzed by a chiral nonracemic C2-symmetric 2,2'-bipyridyl copper(II) complex.
Enantioselective Friedel-Crafts alkylation reactions of a series of substituted indoles with methyl trifluoropyruvate, catalyzed by a chiral nonracemic C(2)-symmetric 2,2'-bipyridyl copper(II) triflate complex, are described. The corresponding 3,3,3-trifluoro-2-hydroxy-2-indole-3-yl-propionic acid methyl esters were formed in good yield and in high enantiomeric excess (up to 90%). This is the first report of the use of a chiral nonracemic 2,2'-bipyridyl ligand in catalytic and enantioselective Friedel-Crafts alkylation reactions. The structural characterization of a copper(II) chloride complex of the chiral 2,2'-bipyridyl ligand by X-ray crystallography is also presented. [reaction: see text]
Lyle
Michael P A
MP
Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Draper
Neil D
ND
Wilson
Peter D
PD