The Research Of Synthesis, Property And Metal Complexes Of Novel N-Heterocyclic Carbene

The thesis is mainly focused on the synthesis of novel N-heterocyclic carbene (NHC) ligands and their transition metals (metal=Ru, Rh and Pd) complexes, and the investigation of their properties. The thesis includes three parts as followed.1. On the basis of our previous work, we used formamidine as starting materials, and synthesized a serious of functionalized imidazoliniums by the ring opening of epoxides. These functional groups include bromine, ester, ether and vinyl group. With these functional groups, we can do further modification to the corresponding carbene ligands.2. We successfully prepared abnormal oxazole and thiazole carbene ligand precursors by intramolecular cyclization in the presence of Tf2O/NEt3, the carbene carbon of which is located in C4. Moreover, we also obtained Rh complexs of these abnormal carbene ligands, and the representative complexs were comfirmed by X-ray single crystal diffraction.3. We further applied Tf2O/NEt3cyclization system in the preparation of various saturated and unsaturated N-heterocyclic carbene precursors successfully. This strategy of cyclization is simple, direct and versatile, and can be used to prepare carbene ligands which are not accessible using previously reported methods. Additionally, this method can also be used to transform the formamides, the common decomposition by-products of saturated NHCs, to useful N-heterocyclic carbene precursors.