title: Catalytic, asymmetric alpha-chlorination of acid halides.
abstract: We present a full account of a tandem catalytic, asymmetric chlorination/esterification process that produces highly optically enriched alpha-chloroesters from inexpensive, commercially available acid halides using cinchona alkaloid derivatives as catalysts and polychlorinated quinones as halogenating agents. We have performed kinetics and control experiments to investigate the reaction mechanism and establish conditions under which the reactions can be best performed. We have developed NaH and NaHCO3 shuttle base systems as the easiest and most cost-effective ways of conducting the reactions, rendering the methodology economically competitive with known chiral halogenation procedures. We have also demonstrated the utility of our reactions by converting the products to synthetically useful derivatives.
authors.affiliation: Department of Chemistry, New Chemistry Building, Johns Hopkins University, Baltimore, Maryland, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: France
authors.forename: Harald
authors.initials: H
authors.lastname: Wack
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Taggi
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Hafez
authors.forename: Ty R
authors.initials: TR
authors.lastname: Wagerle
authors.forename: Meha H
authors.initials: MH
authors.lastname: Shah
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Dusich
authors.forename: Thomas
authors.initials: T
authors.lastname: Lectka