Synthesis Of Polymer Monomer By Carbonylation Reaction

Propylene oxide and 1,3-butadiene are widely available and inexpensive bulk petrochemicals.They can be carbonylated to produce high value-added monomers,such asβ-butyrolactone and adipic diacid or diester.By ring-opening polymerization,β-butyrolactone can be used to produce poly 3-hydroxybutyrate,a kind of biodegradable plastic.Adiponic acid can be used to manufacture Nylon-66,a kind of useful engineering material.The research topic of this dissertation is developing catalytic systems for transition metal-catalyzed carbonylation of propylene oxide and1,3-butadiene to synthesizeβ-butyrolactone and adiponic ester,respectively.The topic consists of two parts:（1）Cobalt-catalyzed carbonylative ring expansion of epoxides toβ-butyrolactone promoted by gallium porphyrinA series of Ga（Ⅲ）porphyrin complexes were developed by virture of the oxygenophilic nature of the group ⅢA element Ga and the larger radius of the Ga³⁺ion.These complexes can be used as Lewis acid catalysts in synergy with carbonyl cobalt complexes in the carbonylative ring-expansion of propylene oxide for the synthesis ofβ-butyrolactone.The conventional water-sensitive Al（Ⅲ）or toxic Cr（Ⅲ）complexes were replaced with our catalyst systems.The Ga（Ⅲ）catalysts exhibited high catalytic activity and selectivity comparable to the catalyst systems consisting of Al（Ⅲ）or Cr（Ⅲ）.The binary catalyst consisting of（TPP）Ga Cl and Co₂（CO）₈ was utilized for the smooth conversion of a series of ethylene oxide derivatives to the corresponding lactone products in moderate to excellent yields.The high activity and durability of the catalyst system was demonstrated by repeated experiments with（TPP）Ga Cl,with a total TON of 16960 based on Ga after 10 cycles.A large-scale reaction was carried out under lower catalyst loading（S/C=2000/1）reaction conditions,yielding 285 g ofβ-butyrolactone in an isolated yield of 83%.These experimental results fully demonstrated the potential application of the developed cobalt-Ga（Ⅲ）porphyrin catalyst for the preparation ofβ-butyrolactone by the carbonylation reaction of propylene oxide with carbon monoxide.（2）Synthesis of adiponic diester by palladium-catalyzed bis-hydroestification of 1,3-butadieneA series of diphosphine ligands,bearing both bulky electron-rich di-tert-butylphosphine fragments promoting the alkene isomerization and 2-pyridyl-tert-butylphosphine moiety promoting the formation of reactive palladium-hydride species and accelerating the alcoholysis of pallaidum-acyl intermediate,were prepared.The application of these ligands in the Pd-catalyzed alkoxycarbonylation of 1,3-butadiene was performed and the optimal reaction conditions（temperature 120 ^oC,CO pressure40 bar,solvent ⁿBu OH,reaction time 24 h）were determined.