Palladium-catalyzed Telomerization Of 1,3-butadiene For The Preparation Of Monomers

With annual global production of over millions of tons per year,1,3-butadiene plays an important role in petrochemical production.It is regarded as an important monomer for polymer production.The telomerization of 1,3-butadiene is endowed with remarkable efficiency of carbon-chain elongation and the obtained value-added products possess the useful olefinic units,which can be further utilized in the synthesis of polymers.Thus,the topic of this dissertation is developing new catalytic systems for the telomerization of 1,3-butaidne with CO₂ or water,which can be used to prepare valuable monomers or intermediates for preparing polymers.The dissertation consists of two parts:（1）Palladium-catalyzed telomerization of 1,3-butadiene with carbon dioxideBy introducing hydroxyl group into PPh₃ ligand,a promoter-free palladium catalytic system based on（p-HOC₆H₄）PPh₂ ligand was developed for the telomerization of 1,3-butadiene with CO₂.High activity and selectivity towards CO₂-incorporated divinylδ-lactone-1 monomer were achieved(TON/TOF up to 4540/568 h^-1,97%selectivity).The key role of phenolic hydroxyl group in attaining high activity was validated.The good performance of large-scale reaction in batch reactor demonstrated the potential utility of this simple catalytic system in valorizing CO₂ with bulk chemical feedstock.（2）Palladium-catalyzed telomerization of 1,3-butadiene with waterSince 2,7-octadienol（1-OD）is utilized as an intermediate of nylon monomer（PA9T）,palladium-catalyzed 1,3-butadiene,one of the most convenient and efficient route for the synthesis of this compound,receives more and more attention.Herein,we studied this reaction and developed a reaction system with DMF as solvent,PPh₃-Pd as catalyst,and potassium bicarbonate as additive.The activity of this reaction system was compared to the reaction activity in the previous literature.TON was improved from590 to 2116.