(8-PQ)Pd(Me)Br, and (i-Pr-DAB)Pd(C(O)Me)Cl. Flexible bidentate nitrogen ligands greatly enhance the reaction, owing to the easy formation of an accessible site on the metal center. The insertion of allenes into the Pd−C bonds of complexes containing rigid bidentate nitrogen ligands probably proceeds via initial allene association followed by either halide or nitrogen dissociation and subsequent migration
丙二烯丙二烯和1,2-庚二烯在配合物(N⌒N)Pd(R)X(N⌒N= 8-PQ,p -An- BIAN ,i -Pr-
DAB,p -An-
DAB,i -Pr-PyCa; R = Me,C(O)Me,C(O)Ph,C(O)i-Pr; X = Cl,Br)已被研究。(8-PQ)Pd (1-3-η)-
2-甲基丙烯基} Cl的X射线晶体结构测定显示出氮
配体的出乎意料的单齿配位。通过NOE NMR实验证明了非极性溶剂中的单齿配位和极性溶剂中的双齿配位。动力学测量表明,该反应在
钯浓度中是一级反应,并且通过与异
戊烯浓度无关和依赖的途径发生。含有柔性二齿氮
配体的配合物的反应被另外的游离二齿氮
配体延迟,这表明氮供体的初始解离是反应中的重要步骤。我们有充分的迹象表明,R基团向预配位的异
戊烯的迁移是决定速率的步骤。-(X =
氯- ,
溴- ),将反应的增强在复合物的情况下,已经观察到(8-PQ)的Pd(Me)