Synthesis, Structural Characterization And Catalytic Application Of New Cubane-Type Molybdenum-Sulfur Clusters

New heterobimetallic cubane-type clusters with Cp* (Cp*=η5-C5Me5) ligand were synthesized and the catalytic activities of these complexes for hydroformylation and Friedel-Crafts reaction were investigated in this thesis.By the [3+1] building block strategy, three new heterobimetallic clusters with Cp* ligand [Cp*3Mo3Co(CO)(μ3-S)4], [Cp*3Mo3Co(CO)(μ3-S)4][PF6], [Cp*3Mo3Rh(cod)(μ3-S)4][PF6]2 (cod=η4-1,5-C8H12) were synthesized through the precursor of incomplete cubane-type cluster [Cp*3Mo3(μ2-S)3(μ3-S)][PF6] with Co2(CO)8 and [Rh(cod)][PF6]. Moreover, these clusters was characterized by nuclear magnetic resonance, infrared spectroscopy, mass spectrometry and X-ray single crystal diffraction. The results shows that all of them contain a cubane-type [Mo3S4M'] cores. Preliminary study on olefins hydroformylation catalyzed by the complex [Cp*3Mo3Rh(cod)(μ3-S)4][PF6]2 was also investigated and up to 94.4%yield of aldehyde was obtained under optimal conditions. However, the ratio of nor/iso of aldehyde was only 1.7/1.Then, we studied the Friedel-Crafts reaction of arenes with allylic alcohols catalyzed by the cubane-type cluster [Cp*3Mo3Pd(dba)(μ3-S)4][PF6] (dba= dibenzylideneacetone). First, we chose cinnamyl alcohol with N,N-dimethylbenzenamine as the model reaction. The optimal reaction conditions was obtained as follows:a homogeneous mixture of equivalent cinnamyl alcohol and N,N-dimethylbenzenamine,5 mol%catalyst, and 0.5 equiv H3BO3as additive were reacted in CH2Cl2 at reflux under Ar. After having established the optimal conditions, the catalytic system was applied to a variety of subsituted arenes and aromatic/aliphatic alcohols with up to 91%isolated yield. The results suggests that aromatic alcohols and electron-rich arenes have a higher reactivity. Moreover, the reaction proceeds with excellent regioselectivity to obtain linear products and the allyl group is more inclined to occupy the para-position of phenyl ring. The Cp*3Mo3S4 fragment could be regarded as a bulky ligand to provide steric hindrance avoiding the formation of branched products. Proposed mechanism for the reaction was also discussed.