Synthesis of enantiomerically pure beta- and gamma-amino acid derivatives using functionalized organozinc reagents

beta-Amido zinc reagents 4 and 5 readily undergo beta-elimination when prep ared in THF, but when a polar aprotic solvent such as DMF is employed, beta -elimination is suppressed. Using DMF, reaction of 4 with aryl iodides prov ides beta-homophenylalanine derivatives (12 examples, 20-89% yield), and an alogous reactions of 5 give gamma-bishomophenylalanine derivatives (7 examp les, 34-80% yield). The related zinc/copper reagents 17 and 18 are also use ful intermediates that undergo subsequent cross-coupling reactions with a w ide range of electrophiles (9 examples, 28-87% yield).