Synthetic Applications of the beta-Lithiation of beta-Aryl Secondary Amides: Diastereoselective and Enantioselective Substitutions.
The sequence of beta-lithiation and electrophilic substitution of beta-aryl secondary amides is reported. The lithiations occur regioselectively at the beta-position, and the resulting lithiated intermediates can be reacted with a wide range of electrophiles to give substituted products. Reactions of beta-lithiated amides bearing an alpha-substituent provide substituted products with high diastereoselectivity. Electrophilic substitutions of beta-lithiated N-methylamides in the presence of the chiral diamine (-)-sparteine provide highly enantioenriched products. The methodology is used to synthesize enantioenriched beta-aryl beta-substituted amides, acids, and lactones.
Lutz
Gary P.
GP
Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
Du
Hua
H
Gallagher
Donald J.
DJ
Beak
Peter
P