Zero-Valent Amino-Olefin Cobalt Complexes as Catalysts for Oxygen Atom Transfer Reactions from Nitrous Oxide

Abstract

The synthesis and characterization of several zero-valent cobalt complexes with a bis(olefin)-amino ligand is presented. Some of these complexes proved to be efficient catalysts for the selective oxidation of secondary and allylic phosphanes, as well as diphosphanes, even with a direct P-P bond. With 5 mol % catalyst loadings the oxidations proceed under mild conditions (25-70 °C, 7-22 h, 2 bar N₂ O) and afford good to excellent yields (65-98 %). In this process, the greenhouse gas N₂ O is catalytically converted into benign N₂ and added-value organophosphorus compounds, some of which are difficult to obtain otherwise.

Keywords: N2O activation; cobalt; nitrous oxide; phosphane oxidation.