Synthesis Of Novel Tetradentate Phosphine Ligand And Its Application In Hydroformylation Of Mixed Butenes

Aldehydes are important starting materials and intermediates for many chemical and pharmaceutical products.In 2019,the worldwide production of aldehydes exceeded 15 million tons.Aldehydes are widely used,for example,n-valeraldehyde is used internationally to produce non-toxic,environmentally friendly macromolecular plasticizer Di(2-propylheptyl)phthalate(DPHP).As a new type of plasticizer,DPHP has a very good market prospect for replacing the traditional plasticizer Dioctyl Phthalate(DOP)produced by propylene.The synthesis method of n-valeraldehyde is prepared by hydroformylation of mixed C4.The annual output of mixed C4 is 35 million tons in China,the price is less than half of propylene,so the market is very competitive,but because its main component contains internal olefins(i.e.cis,trans-2-butene),resulting in poor hydroformylation activity and low selectivity.Phosphorous containing ligands have played a crucial role in olefin hydroformylation which promote the industrial application of hydroformylation reactions.Synthesis of phosphorous containing ligands that can improve the reaction speed,selectivity(l/b ratio),stability and separation are the current industrial research hotspot.In this paper,a large hindered biphenyl skeleton was synthesized by oxidative coupling,and then a new generation of highly hindered tetradentate phosphite ligand was synthesized,which developed a simple and efficient ligand synthesis route to provides the possibility for its industrial application.This dissertation explored its application in mixed C4 hydroformylation reactions.By screening the optimal reaction conditions,at reaction temperature 40 to 80 ?,a conversion rate of 96.2% and l/b ratio 30.3 was achieved.Meanwhile,a chiral tetradentate phosphite ligand with large steric hindrance was also synthesized,which expanded the development of multidentate Phosphorous ligands in asymmetric hydroformylation.