双功能配体修饰的Ir催化剂在“氢甲酰化-缩醛化”串联反应中的共催化作用  

Co-catalysis over Bi-functional Ligand Based Ir-catalyst for Tandem Hydroformylation-acetalization Reaction

作　　者：杨妲 张龙力 刘欢 杨朝合[2] Da Yang;Longli Zhang;Huan Liu;Chaohe Yang(College of Science,China University of Petroleum(East China),Qingdao 266580,China;State Key Laboratory of Heavy Oil Processing,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)理学院,青岛266580 [2]中国石油大学(华东)重质油国家重点实验室,青岛266580

出　　处：《化学学报》2021年第5期658-662,共5页Acta Chimica Sinica

基　　金：中国博士后科学基金(No.2019M662460);自主创新科研计划项目(No.20CX06033A)资助.

摘　　要：通过对双齿膦配体的单P原子定向甲基化,合成了两种离子型“叔膦-季鏻鎓Lewis酸”双功能配体L2和L3,该类双功能配体分子结构中既含有与过渡金属配位的叔膦基团,又含有具Lewis酸的季鏻鎓基团.研究结果表明,在合成气的体积比(CO/H2)为4∶1时,双功能配体L2修饰的[Ir(COD)Cl]_(2)催化剂高效催化烯烃的“氢甲酰化-缩醛化”串联反应,1-辛烯的转化率为98%,缩醛的选择性高达86%,其催化活性好于同等条件下的Rh催化剂.双功能配体L2与[Ir(COD)Cl]2原位构建的共催化体系的催化效果远优于Ir(I)配合物和季鏻鎓Lewis酸的物理混合;同时还表现出较好的底物普适性.此外,由于双功能配体L2的高极性,其修饰的Ir催化剂可以顺利实现与正己烷溶液的分离,从而实现催化剂的回收循环使用.The ionic bi-functional ligands of L2 and L3 in combination of a phosphine with a Lewis acidic phosphonium were synthesized through selective quaternized by MeI at the one P-position of the bi-dentate ligands.Due to the separation by the rigid ring,the incorporated-PPh2 and the Lewis acidic phosphonium were well retained without quenching problem.In the bi-functional ligands,the phosphine group could coordinate with transition metals,the phosphonium group could pre-sent Lewis acidic.The Ir(I)-complex modified by the“phosphino-phosphonium”bi-functional ligand(L2)was used to cata-lyze the tandem hydroformylation-acetalization of olefins.Under the optimized conditions([Ir(COD)Cl]_(2)0.025 mmol,L20.025 mmol,1-octene 5.0 mmol,methanol 5.0 mL,N-methyl pyrrolidone 2.0 mL,VCO/VH2=4∶14.0 MPa,temperature 120℃,reaction time 8 h),the conversion of 1-octene was 97%with the selectivity of acetals up to 86%,which was analyzed by GC and GC-MS.In this system,the activity of Ir catalyst was better than that of Rh catalyst at same conditions.It was found that L2-modified[Ir(COD)Cl]_(2) could also efficiently accelerate this tandem reaction,which proved more effective than the ligands lacking phosphonium or the mechanical mixtures of the individual functional groups independently.It was be-lieved that,in L2,the phosphonium not only acted as a Lewis acid organocatalyst to drive the sequential acetalization of al-dehydes,but also contributed to the synergetic catalysis for the preceding hydroformylation through stabilizing the Ir-acyl intermediate with the phosphine cooperatively.The L2-[Ir(COD)Cl]_(2) system is also generally applied to the tandem hydro-formylation-acetalization reaction of a wide range of olefins in different alcohols,give the yields of products in the range of 45%~87%.Advantageously,as an ionic ligand with high polarity,L2-based Ir(I)-catalyst could be precipitated by n-hexane upon completion to fulfil the recovery and recycling uses of transition metal catalysts.

关 键 词：氢甲酰化 缩醛化 串联反应 双功能配体 铱催化剂 

分 类 号：O621.251[理学—有机化学] O641.4[理学—化学]