Hydrogenation of α-enaminoketones with cobalt phosphine-modified catalysts

The synthesis of α-enamines and hydrogenation of these compounds were studied using cobalt-modified complexes. Cobalt complexes were characterized by 1H, 13C and 31P NMR, elemental analysis and IR spectroscopy. Furthermore, the molecular structures of complexes C1–C2 and C4–C5 have been determined by single-crystal X-ray diffraction. All cobalt complexes investigated were active catalysts for the hydrogenation reaction. The best catalytic activity was obtained with an ortho-substituent in the phosphine ligand. Noteworthy, the reduction was chemoselective over the double bond.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The first example of catalytic hydrogenation of α-enamino-ketones with L(CO)3Co–Co(CO)3L ► Good yields of secondary α-amine-ketones were obtained. ► Completely chemo selective reaction ► Ortho-substituted phosphines gave the best results.