Preparation of 1-octene by ethylene tetramerization with high selectivity

Two novel PNP ligands have been synthesized and characterized by 1H-NMR, elemental analysis, and mass spectra. In combination with Cr(III) and cocatalyst MAO, they generate active catalytic systems that tetramerize ethylene with both high catalytic activity and high selectivity to produce 1-octene. The results show that these catalyst systems are able to catalyze ethylene tetramerization, with high catalytic activity up to 0.89×106 g/mol Cr.h, and the selectivity of C8 in products is 72.52%, and the percentage of 1-olefins in the C8 cut is 97.87%.