سنتز، شناسايي و كاربرد كاتاليستي كمپلكس هاي ارتو پالاديت 4- نيتروبنزوئيل متيلن تري فنيل فسفوران

چكيده انگليسي :

Synthesis Characterization and Catalytic Application of Orthopalladated Complexes 4 Nitro benzoyl methylene tri phenyl phosphorane Mina Salimian m salimian@ch iut ac ir Date of Submission 2011 1 4 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Kazem Karami Karmi@cc iut ac ir Abstract In this thesis phosphorus ylides PhBPPY and NO2BPPY have been synthesized through the formation of phosphonium salt and dihydrogenation followed by the reaction of Pd OAc 2 and the orthopalladated dinuclear complexes Pd R NO2 BPPY 2 R Cl Br and I have been prepared The reaction of dinuclear complexes and monodentate ligands L 4 methyl prydine 4 MePy 2 4 6 symcollidine 2 4 6 Me3Py PPh3 giving the stabilized mononuclear orthopalladated complexes Pd Br NO2BPPY 4 MePy Pd Br NO2BPPY PPh3 Pd Br NO2BPPY Me3Py Pd Cl NO2BPPY PPh3 and Pd Cl Me3Py NO2BPPY in endo position The complexes were chracterized by FT IR NMR UV Vis and X ray diffraction study of Pd 4 MePy NO2 BPPY Br Pd Br NO2BPPY On the other hand the nucleophilic treatment of phosphosrus ylide have been studied by the reaction of PhBPPY with Pd COD Cl2 that led to monomeric complex PdCl2 C8H12 CH PPh3 COC6H4 4 Ph The CO band which is sensitive to complexation occurs from 1507 and 1521 cm 1 in the parent ylides These bands appear at lower energies compared to that found in the phosphonium salts due to the charge delocalization present in such compounds Coordination of ylide through the carbon atom causes an increase in the CO band The FT IR spectra of all complexes show a strong absorption in the range of 1621 1637 cm 1 which have been shifted to higher frequency with respect to the parent ylides meaning that the ylides are C bonded to the palladium center The P C band frequencies occur at 881 and 860 cm 1 in the parent ylides PhBPPY and NO2BPPY respectively and are shifted to lower frequencies for the complexes 852 854 suggesting some removal of the electron density of the P C bonds The 1H NMR signals for the PCH group of complexes are shifted downfield compared to that of the free ylides as a consequence of the inductive effect of the metal center In the 1H NMR spectra for dinuclear complexes the signals due to the methinic proton were broad minor or broad doublets major The presence of two lines of different intensity on each spectrum can be originated from the presence of two diasteroisomers RR SS and RS SR as a result of the C bonding of the ylide and the dinuclear nature of Pd R NO2 BPPY 2 R Cl Br I The 1H NMR spectrum of PdCl2 C8H12 CH PPh3 COC6H4 4 Ph shows a signal in 1 77 ppm that refers to the CH of 1 5 cyclooctadien that bonded to metal and shifted downfield compared to other hydrogens of this ligand as a consequence of the inductive effect of the metal center In the 31P 1H NMR spectra of all complexes the presence of one signal group confirm a single isomer for each complexes The UV Vis spectrum of the ligand NO2BPPY shows three peaks in 200 400 nm correspond to ligand field transition or n and transitions The UV Vis spectra of complex show only two peaks in UV region because of the coordination of ligand to metel and double bond P C reformed to single bond For these complexes no peaks appear in visible region because d d transitions are laporte forbidden Single crystals of Pd Br 4 MePy NO2BPPY and Pd Br Me3Py NO2BPPY suitable for X ray crystallography were obtained Although the orthometallated ligand is remarkably warped the environment around the Pd is planar In the last section these complexes are used in Suzuki coupling and high yields of reactions demonstrate catalytic properties of these complexes Key words Phosphorus ylides Palladium II complexes Suzuki coupling

سليميان، مينا

سنتز، شناسايي و كاربرد كاتاليستي كمپلكس هاي ارتو پالاديت 4- نيتروبنزوئيل متيلن تري فنيل فسفوران

سيكلوپالاديشن , حمله ي نوكلئوفيلي , سيكلواكتادي ان , فسفرايليد , كوپل سوزوكي