两相体系中含氮双齿膦配体对1-十二烯氢甲酰化反应的影响

含氮双齿膦配体(Ph2PCH2)2NCH2CH2OCH2CH2NHCH2CH2PO3Na2(以A表示)在1-十二烯的氢甲酰化反应中的实验结果表明双膦配体的螯合作用降低了催化活性和有利于直链醛的生成.A与水溶性催化剂RhCl(CO)(TPPTS)2在合成气氛下发生配体交换后,形成配合物HRh(CO)(A)(TPPTS),其催化活性比单膦-铑配合物的催化活性更低.又由于双膦与铑配位后形成的络合物中铑的配位空间更拥挤,因此1-十二烯的端碳原子更容易与铑中心络合配位,形成直链烷基-铑络合物,使得产物醛中直链醛的含量增大.

Effect of diphosphine ligand with N atom on 1- dodecene hydroformylation in biphasic system

The lower catalytic activities and the more linear aldehydes in the presence of diphosphine with N-atom((Ph2PCH2)2NCH2CH2OCH2CH2NHCH2CH2PO3Na2,named A) can be attributed to the stabilization of rhodium complex by the chelation of diphosphine ligand in 1-dodecene hydroformylation reaction.After the exchange of ligands between A and water-soluble catalyst in the presence of H2/CO,new complex HRh(CO)(A)(TPPTS) is formed,whose catalytic activity is better than that of monophosphine-Rh-complex.Owing to the chelation of diphosphine ligand with the metal center,the coordination environment of rhodium complex becomes more congested.Accordingly,less crowed linear alkyl-rhodium intermediate is favorably formed;thereby the yield of linear aldehyde in the product increases.Cationic surfactant cetyltrimethyl ammonium bromide(CTAB) is effective for accelerating 1-dodecene hydroformylation in the organic-aqueous biphasic system.