METAL COMPLEXES OF BIOLOGICALLY IMPORTANT LIGANDS .91. INTRODUCTION OF ORGANOMETALLIC FRAGMENTS INTO ALPHA-AMINO-ACIDS BY REACTIONS OF ALPHA-BROMOGLYCINE DERIVATIVES WITH ANIONIC ORGANOTRANSITION-METAL COMPOUNDS

The reactions of protected alpha-bromoglycine esters R(1)(O)CNHCH(Br)C O(2)R(2) (R(1) = Ph, OCMe(3); R(2) = Me, tBu) with organometallic anio ns of acetylferrocene, CpFe(CO)(PPh(3))C(O)CH3, (OC)(5)M=C(OMe)CH3 (M = Cr, W), (OC)(3)Cr(eta(6)-diphenylmethane), (OC)(3)Cr(eta(6)-fluorene ), (OC)(3)Cr(eta(6)-dihydroanthracene) and of (OC)(3)Cr(eta(6)-aniline ) and (OC)(3)Cr(eta(6)-o-toluidine) provide a method for the introduct ion of organometallic fragments into the side chains of alpha-amino ac ids. The complexes may be useful as markers for alpha-amino acids in p eptides. The compound OC)(3)Cr(eta(6)-o-C6H4(CH3)NHC(H)(CO(2)Me)NHC(O) Ph was characterized by X-ray diffraction.