H. Sajiki et K. Hirota, Formation of Pd/C-ethylenediamine complexes [Pd/C (en)] and it's application to selective hydrogenations, J SYN ORG J, 59(2), 2001, pp. 109-120
The chemoselective hydrogenation of an organic compound containing two or m
ore reducible functional groups is a useful method in organic synthesis. We
have found that a Pd/C catalyst formed an isolable complex with the ethyle
nediamine (en) employed as catalytic poison, and its complex catalyst [Pd/C
(en)] chemoselectively hydrogenated a variety of reducible functionalities
distinguishing O-benzyl, N-Cbz and O-TBDMS protective groups, benzyl alcoho
ls and epoxides. The catalyst also regioselectively hydrogenolyzed 1,2-epox
ides to sec-alcohols depending upon the employed reaction conditions.