【作者】 李平；

【导师】 王洪星；

【作者基本信息】 天津大学 ， 有机化学， 2013， 硕士

【摘要】 钳型化合物（Pincer complexes）在诸多领域有着广泛的应用，因其独特的结构特点使其具有优良的催化功效，所以成为近年来研究的一个热点。本文以5叔丁基2溴1,3苯二甲醛、2溴1,3苯二甲醛以及5硝基2溴1,3苯二甲醛为起始原料，分别与取代苯胺缩合得到三个系列的新型NCN双西弗碱配体，后者与Pd2(dba)3在无水甲苯的条件下通过对C Br键氧化加成得到高收率的三个系列的PdII NCN But，PdII NCN H及PdII NCN NO2钳形化合物。上述各步产物的结构均经过元素分析、IR、1H NMR、13C NMR证实。5叔丁基2溴1,3双[苯基(氨基次甲基)]苯的钯化物(9c)及5硝基2溴1,3双[苯基(氨基次甲基)]苯的钯化物(13c)的结构也经X-ray得到进一步的证实。同时探讨了取代基电子效应及空间效应对钳型化合物生成的影响。研究了上述PdII NCN钳形化合物在Sonogashira反应中的催化应用：考察了PdII NCN钳形化合物中不同位置上(氨基次甲基苯环：Z=But，H，NO2；与氮原子直接相连苯环：R)的取代基对催化性能的影响，同时也对偶合试剂芳卤上的卤原子种类、取代基类别、助剂等各种条件进行了评估。优化了最佳偶合条件并比较三个系列PdII NCN化合物的催化活性进而得出最优催化剂系列，结果表明：PdII NCN NO2系列的钯化物在三个钯化物系列中对Sonogashira偶联反应的催化效能最好。在三个系列PdII NCN化合物催化剂横向比较中，考察苯胺环上取代基的效应时，并无明显的规律可循。偶合反应中，碘苯与苯乙炔的催化产率最高，芳溴次之，芳氯最差，这和它们的碳卤键的键能大小是一致的。此外在助催化剂三苯膦的存在下上述偶合要比没有三苯膦的情况催化收率高。芳卤上的取代基效应较为明显：吸电子的芳卤的偶合产率明显高于供电子的芳卤的偶合产率。更多还原

【Abstract】 Pincer complexes are widely used in many fields. Recently, pincer complexeshave attracted much attention because of their widely used as catalysts in organicsynthesis for their unique structures. Three series NCN diimine ligands were obtainedafter condensation of5But2bromoisophthalaldehyde,2bromoisophthalaldehydeand5nitro2bromoisophthalaldehyde with substituted anilines. Treatment of theseligands with Pd2(dba)3in anhydrous toluene by oxidative addition of C Br bondresulted in the corresponding PdII-NCN-But, PdII-NCN-H and PdII-NCN-NO2pincercomplexes. The PdII-NCN pincers and their precursors as mentioned above were fullycharacterized by elemental analysis, IR,1H NMR,13C NMR spectroscopy. Thestructures of4tert butyl2,6bis(imino)isophthalaldimin2yl palladium(II) bromide(9c) and4nitro2,6bis(imino)isophthalaldimin2yl palladium(II) bromide (13c)were further confirmed by X-ray single crystal diffraction. The influences of theelectronic effect and spatial effect of substituent on the formation of these PdII-NCNpincers were also discussed.The application of PdII-NCN pincers in Sonogashira coupling reactions was alsostudied. The impact of substituents Z=But, H, NO2as well as R on the catalyticactivities in Sonogashira coupling were investigated. In addition, the different haloatoms, the nature of substituent and co-catalyst (PPh3) were assessed. Finally, thereaction conditions were optimized. The comparison of these three series pincers ledto the best catalyst system. All these results demonstrated that the PdII-NCN-NO2pincers exhibited the highest coupling yields. No trend was obviously observedregards to the substituents effect in aniline ring on the Sonogashira coupling. In thecoupling, the iodobenzene normally gave the highest coupling yield, while the thechlorobenzene was the lowest, which was in consistence with the C X bond energy.With the help of co-catalyst (PPh3), the Sonogashira coupling always gave the highercoupling yields. A phenomenon that halobenznes containing the electron-withdrawinggroups improved the catalytic yields than those bearing electron-donating groups wasalso observed.更多还原