Nalchigar , S.; Taghizadeh Ghoochany , L.; Dehe , D.; Sun, Y.;

1. Novel PyrimidylPhosphine Palladium Complexes and Application as Homogeneous and Heterogeneous Catalysts for the Suzuki Cross- Coupling Reactions Nalchigar, S.; TaghizadehGhoochany, L.; Dehe, D.; Sun, Y.; Thiel, W. R., Technische Universität Kaiserslautern, Gottlieb-Daimler Str., Geb. 54, 67663, Kaiserslautern, Germany Introduction On continuing our efforts to develop synthetic pathways for phosphine ligands bearing pyrazoles and pyrimidines, and on investigating their activity as ligands in homogeneous and heterogeneous catalysts,[1-3] we have recently found a new synthetic route for the precursor 1, which we were able to scale it up to 1 kg with more than 90% yield. This route is shorter and cheaper than other procedures.[4] Ligand Synthesis, Structures Starting from 2- or 4-fluoroacetophenon, the acyl group is converted into 3-dimethylamino-2-propen-1-onyl unit, which was achived by reaction with HC(O-Me)2NMe2 (DMFDMA). This product underwents a new coupling reaction with diphenyl(trimethylsilyl)phosphine and CsF as catalyst to yield 1. Ring closure of 1 with an excess of substituted guanidines (a-e) gave the desired ligands (2a-e). Palladium Complexes PN & PP palladium complexes were synthesized by using the titled ortho or para substituted ligands, respectively. Pd Supported Materials The complexes were covalently anchored onto MCM-41 or SiO2 starting from 2-a in three steps. Although 0.4 mmol of complexes per gram of support were applied in the third step, elemental analysis shows loadings betwen 0.1 to 0.4 mmol/g. (A, 0.31; B, 0.28; C, 0.15; D, 0.1 mmol/g) Crystal structure of cis-dichlorobis{[2-(4-(2-amino)pyrimidinyl) phenyl]diphenylphosphine} palladium(II) (PdL1) Surface study Characterization of the functionalized materials by N2 adsorption, XRD & SEM indicates, that structure of MCM-41 remains through the grafting procedure. PdL1@MCM-41 PdL1@SiO2 PdL1@MCM-41 PdL1@SiO2 PdL2@MCM-41 PdL2@SiO2 Catalysis The examination of Suzuki cross-coupling reactions of various aryl halids with phenylboronic acid is underway. Some results are shown bellow. CP-MAS NMR Solid-state CP-MAS NMR spectroscopy (13C, 29Si and 31P) demonstrates that the titled complexes are grafted successfully into the support and the structures of the complexes are preserved during the grafting process. Selected spectra of PdL1@MCM-41 are shown bellow. MCM-41 XRD & SEM of PdL1@MCM-41 13C CP-MAS NMR of PdL1@MCM-41 39P CP-MAS NMR of PdL1@MCM-41 PhX (1mmol); PhB(OH)2 (1.5 mmol); base (1.2 mmol); Pd (1 mol% relative to aryl halide) 29Si CP-MAS NMR spectra provide direct evidence for the incorporation of the covalently linked organic system. Further Ligand Variations, Outlook By using different R groups, the electronic situation of the palladium center will change, These ligands can be synthesied by the route shown bellow. PdL1@SiO2 PdL1@MCM-41 Refs.: [1] Y. Sun, W. R. Thiel, Inorg. Chim. Acta. 2006,359, 4807. [2] S. Shylesh, L. Wang, W. R. Thiel, Adv.Synth. Catal. 2010, 352, 425. [3] S.Shylesh, v. schünemann, W. R. Thiel, Angew. Chem. Int. Ed. 2010, 49, 3428. [4] Y. Sun, A. Hienzsch, J. Grasser, E. Herdtweck, W. R. Thiel, J. Organomet. Chem. 2006, 691, 291.