Asymmetric synthesis of alpha-branched primary amines on solid support vianovel hydrazine resins

Two novel chiral hydrazine resins for asymmetric solid-phase synthesis have been developed. The enantiopure beta -methoxyamino auxiliaries, derived fr om trans 4 hydroxy (S) proline and (R) leucine, were attached to Merrifield resin and transformed into their corresponding hydrazines. Immobilization of various aldehydes, followed by 1,2-addition of organolithium reagents to the resulting enantiopure hydrazones and reductive cleavage from the solid support, furnished or-branched amines, which were isolated as their corres ponding amides in good overall yields and enantiomeric excesses of up to 86 %.