We communicate a convenient method for the pressure hydrogenation of quinolines in
aqueous solution by using a particulate cobalt-based catalyst that is prepared in
situ from simple Co(OAc)2·4H2O through reduction with abundant zinc powder. This catalytic protocol permits a brisk
and atom-efficient access to a variety of 1,2,3,4-tetrahydroquinolines thereby relying
solely on easy-to-handle reagents that are all readily obtained from commercial sources.
Both the reaction setup assembly and the autoclave charging procedure are conducted
on the bench outside an inert-gas-operated containment system, thus rendering the
overall synthesis time-saving and operationally very simple.
Key words
heterogeneous catalysis - hydrogenation - cobalt - zinc - tetrahydroquinolines