Synthesis of methionine- and norleucine-derived phosphinopeptides

We present herein a straightforward synthesis of N-Fmoc-protected synthons derived from a phosphinic analogue of methionine. These precursors were used successfully for the solid-phase synthesis of methionine-mimic phosphinopeptides using BOP-catalyzed coupling without protection of the phosphoryl moiety. We also prepared a new type of pseudopeptide derived from a phosphinic analogue of norleucine with a –PO(OH)–CH2–COOR moiety.