Efficient Bulky Phosphines for the Selective Telomerization of 1,3-Butadiene with Methanol

摘要

Abstract: A series of bulky phosphines containing substituted biphenyl, 2-methylnaphthyl, or 2,7-di-tert-nbutyl-9,9-dimethylxanthene moiety were prepared. They were used in the preparation of new monophos-nphine palladium(0) dvds complexes, which were employed as catalysts for the selective telomerizationnof 1,3-butadiene with methanol to obtain 1-methoxyocta-2,7-diene (1-MOD), the key intermediate in thenDow 1-octene process. Several ligands showed improved selectivity and yield compared to that of thenbenchmark ligand PPh3. Especially 2,7-di-tert-butyl-9,9-dimethylxanthen-4-yl-diphenylphosphine (4, “mono-nxantphos”) stands out as an excellent ligand in terms of yield, selectivity, and stability.