Neutral dialkyl organolanthanide (YIII, LuIII, ErIII, YbIII) complexes stabilized by tridentate ?N-,N,N? monoanionic thiazole amidopyridinate ligands have been synthesized and completely characterized. In addition to their rich organometallic chemistry, responsible on specific compounds of unprecedented and spontaneous rearrangements occurring at the metal coordination sphere, selected and stable species from this series have shown remarkable activity and selectivity in the intramolecular hydroamination of model amino-alkenes and in diene polymerization. For all experimental trials, cationic monoalkyl counterparts, prepared upon treatment of the dialkyl precursors with an equimolar amount of an organoborate, have shown the best catalytic performance. Cationic thiazole-containing YIII mono-alkyl complexes promote the intramolecular hydroamination of primary and secondary amino alkenes at moderate catalyst loadings (5 mol%) under relatively mild (time and temperature) reaction conditions. In addition, the same system is capable to induce the isoprene (IP) polymerization with an essentially 3,4 atactic structure (92.7%; rr %, 21; mr %, 50; mm %, 29). Other cationic systems from this series (LuIII and ErIII) show the highest activity along with a living character toward IP polymerization, affording PIPs with moderate molecular weights (Mn up to 146000 g/mol) and relatively high trans-1,4-selectivity (up to 76.4%). A full account of the catalytic performance of these organolanthanides in the olefin upgrading will be discussed.
Thiazole Containing Amidopyridinate Organolanthanides: Synthesis and Catalytic Activity in the Intramolecular Hydroamination and Isoprene Polymerization
Luconi Lapo;Rossin Andrea;Giambastiani Giuliano
2016
Abstract
Neutral dialkyl organolanthanide (YIII, LuIII, ErIII, YbIII) complexes stabilized by tridentate ?N-,N,N? monoanionic thiazole amidopyridinate ligands have been synthesized and completely characterized. In addition to their rich organometallic chemistry, responsible on specific compounds of unprecedented and spontaneous rearrangements occurring at the metal coordination sphere, selected and stable species from this series have shown remarkable activity and selectivity in the intramolecular hydroamination of model amino-alkenes and in diene polymerization. For all experimental trials, cationic monoalkyl counterparts, prepared upon treatment of the dialkyl precursors with an equimolar amount of an organoborate, have shown the best catalytic performance. Cationic thiazole-containing YIII mono-alkyl complexes promote the intramolecular hydroamination of primary and secondary amino alkenes at moderate catalyst loadings (5 mol%) under relatively mild (time and temperature) reaction conditions. In addition, the same system is capable to induce the isoprene (IP) polymerization with an essentially 3,4 atactic structure (92.7%; rr %, 21; mr %, 50; mm %, 29). Other cationic systems from this series (LuIII and ErIII) show the highest activity along with a living character toward IP polymerization, affording PIPs with moderate molecular weights (Mn up to 146000 g/mol) and relatively high trans-1,4-selectivity (up to 76.4%). A full account of the catalytic performance of these organolanthanides in the olefin upgrading will be discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.