THE FORMATION OF A NOVEL PD C-ETHYLENEDIAMINE COMPLEX CATALYST - CHEMOSELECTIVE HYDROGENATION WITHOUT DEPROTECTION OF THE O-BENZYL AND N-CBZ GROUPS/

A Pd/C catalyst formed an isolable complex with ethylenediamine employ ed as the catalytic poison via one-to-one interaction between Pd metal and ethylenediamine, and this complex catalyst [Pd/C(en)] chemoselect ively hydrogenated a variety of reducible functionalities such as olef in, acetylene, nitro, benzyl ester, and azido in the presence of an O- benzyl or N-Cbz protective group. These findings reinforce the versati lity potential of O-benzyl and N-Cbz as protective groups in organic s ynthesis, and the Pd/C(en) catalyst has been identified as a novel and chemoselective catalyst for the hydrogenation.