| Increasing attention has been paid to metallocene carbonyl complexes, especially the dinuclear metallocene complexes, due to the significant cooperative effect of both metal centers on their reactivity and catalytic applications. While, for the mononuclear halogenated metallocene carbonyl complex, because of the existence of halogen element makes it better to activate the metal atoms, improve reaction activity. Based on the structure of the catalyst determine its catalytic activity, as a result, the metal complex in catalytic Friedel- Crafts shows very high catalytic activity. Thus it can be seen, intensive study of these complexes are of great significance, Which will not only enrich and develop the metal organic chemistry theory, but also help for the new model of the highly active and selective catalyst and reaction,so it has potential application prospects. This paper synthesized five dinuclear metal carbonyl complexes and studied the reactivity of dual-core substituted tetramethylcyclopentadienyl molybdenum carbonyl compounds with I2. Then, we mainly studied the activity of dual-core molybdenum carbonyl compounds and mononuclear tetramethylcyclopentadienyl molybdenum carbonyl iodides catalytic Friedel- Crafts acylation reaction, optimized the catalyst system and the reaction conditions, investigated the affection factors of reaction activity, respectively discussed the possible mechanism of dual-core molybdenum carbonyl compounds and mononuclear molybdenum carbonyl iodines catalytic Friedel- Crafts acylation reaction. The main results are listed as follows:(1) In this thesis, 5 substituted tetramethylcyclopentadienyl ligands [(C5Me4H)R] [R=nBu(1),tBu(2), allyl(3),Ph(4), Pz(5)] were synthesized. Reactions of the five ligands with Mo(CO)3(Me CN)3 in refluxing xylene gave the corresponding five dinuclear metal carbonyl complexes [(η5-C5Me4R)Mo(CO)3]2 [R= n Bu(6), t Bu(7), allyl(8),Ph(9), Bz(10)].(2) Researched the reactivity of the five dinuclear metal carbonyl complexes with I2, in chloroform solution, and obtained five kinds of mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl iodines [(η5-C5Me4R)Mo(CO)3]I [R= n Bu(11), t Bu(12), allyl(13), Ph(14), Bz(15)].(3) Respectively studied the compounds 6 ~ 15 catalytic Friedel- Crafts acylation reaction of aromatic compounds with a variety of acylation reagents. The results indicatedthat: all the molybdenum carbonyl compounds have obvious catalytic activity in Friedel-Crafts acylation reaction. Relatively, the mononuclear compounds showed higher catalytic activity. Compared with the traditional catalysts, the metal carbonyl complexes have obvious advantages, for example: less dosage, mild reaction condition, high selectivity, no isomerization reaction, simple post-processing, environmental pollution is small, close to the advantages of green chemistry and so on.(4) When Phenylacetyl chloride reacted with aromatic substrates acylation, the conventional product and a small amount of non-target product were obtained; The Benzoyl chloride alone under the action of the catalytic system can react with the organic oxidant o-chloranil directly. By analysis of the non-target product, we designed experiments to further validate the catalytic mechanism.(5) The possible mechanism of Friedel- Crafts acylation reaction was discussed, thus indicating that the substituted tetramethylcyclopentadienyl molybdenum carbonyl compounds/ o-chloranil were act as Lewis acids and the electrophilic-substitution mechanism was involved.(6) All catalytic complexes were characterized by1 H NMR,13 C NMR, IR spectra and elemental analysis. The molecular structures of 8 typical complexes were determined by X-ray diffraction analysis. |
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