This work describes a Pd-catalyzed coupling of ferrocene al-derivative 10) and of course amides. A minor by-product of the coupling reaction, namely the homo-dimer bis(ferrocene kyne derivatives to iodo amino acids. Ferrocene carboxylic acid propargyl amides were easily obtained in high yield. carboxylic acid propargylamide) 9, was identified in the crude reaction mixtures by mass spectrometry and indepen-The crystal structures of the propargyl amine derivative 3 and the 1,1-diethylpropargylamine derivative 4 have been dently synthesized by oxidative coupling (Glaser and Eglington) of 3. All new compounds were completely charac-determined by X-ray diffraction. Pd-catalyzed coupling to piodoanilide amino acids gave the corresponding ferrocene-terized spectroscopically, including 15 N-and 2D NMR spectroscopy, Mössbauer spectroscopy and electrochemistry. This labeled amino acid derivatives, which were easily purified by diethyl ether extraction in the case of the 1,1-diethyl deri-work introduces a versatile procedure for a selective functionalization of amino acids with organometallics at the C-termi-vatives 8. The coupling reaction did not require anhydrous solvents and tolerated a variety of functional groups present nus which is expected to be of general applicability to peptide chemistry. in peptides such as alcohols (8a, Ser), thioethers (8b, Met), disulfide bonds (cystine, 12) esters (as in the N-labeled Leu ever, derivatizing a peptide with alkynyl groups is not feas-Fax: (internat.) ϩ 49-(0)208/306-3951