Palladium Catalyzed Telomerization Of 1,3-butadiene With Methanol Or Malonates

Transforming 1,3-butadiene,one of the most important petrochemical products with worldwide production volumes exceeding millions of tons per year,to valuable commodity chemicals by catalytic methods has long-lastingly received intensive research interests.Palladium-catalyzed telomerization of butadiene with nucleophile constitutes one of the most important transformation.In this context,the detailed contents of this dissertation contains the following two parts:1)Palladium-catalyzed telomerization of 1,3-butadiene with methanolA series of metallocene-based phosphine ligands were designed,synthesized and applied into palladium-catalyzed telomerization of 1,3-butadiene with methanol for improvingthereactionactivityandselectivity.Using ruthenocenyldiphenylphosphine-Pd（ppr-Pd）as the catalyst system in this reaction,the desired product was obtained with a turnover number of up to 2.0×10~5 and in high chemoselectivity and regioselectivity.The results of DFT calculations and control experiments explained the excellent performance of ppr-Pd catalyst and the stability of regioselectivity with the variation of catalyst concerntration in this reaction2)Palladium-catalyzed telomerization of 1,3-butadiene with malonatesWith methanol as solvent and easily available PPh₃ as ligand,an efficient palladium catalyzed telomerization of butadiene with dimethyl malonate was developed with high regioselectivity（n:iso>40:1）and high activity（TON up to 1.6×10~5）.PPh₃-Pd catalyst is also highly active when using other malonates as nucleophiles.The obtained telomer products can be converted into various valuable compounds including 10-hydroxydecanoic acid,undecanedioic acid and 11-hydroxyundecanoic acid via functional group interconversion.The mechanism of the reaction was primarily uncovered based on the controlled experiments.