Mechanistic Investigations and Synthetic Development of (-)-Sparteine Mediated Asymmetric Benzylic Lithiation-Substitution Reactions of Secondary Amides

Abstract

The synthetic utility of the lithiation-substitutions of N-(2-phenethyl)isobutyramide has also been investigated. Enantioenriched substituted products have been carried forward in the synthesis of 1,4-disubstituted dihydro- and tetrahydroisoquinolines. Variation of either substituent is convenient as the 4-position substituent is determined by choice of the electrophile in the lithiation-substitution and the 1-position substituent is introduced prior to cyclization.