The Synthesis And Application Of Organotin Oxo Clusters

Organotin oxo clusters have arisen the interest of chemists due to their excellent catalyst activity in several kinds of organic reactions. The research of the organotin oxo clusters has become one of the most active fields in organotin chemistry. The present thesis primarily involves the following aspects of the synthesis of organotin oxo clusters and their applications in organic reactions:1. Four compounds of tetraorganodistannoxanes were synthesized and characterized by elemental analysis, infrared spectra, multiple NMR (1H, 13C, 119Sn, 19F). The 119Sn NMR revealed that the tetradistannoxanes were ladder dimmer, which contained a symmetric center of Sn2O2 ring. In addition, several non-dimmer chemicals of organotin oxo cluster were synthesized and characterized by multiple NMR. Meantime, the solubility of the synthetic compounds in organic solvent was investigated. It was found that most organotin oxo clusters were dissolvable in organic solvents but not in perfluorinated solvent except [ClR2SnOSnR2Cl]2 (R=C6F13C2H4) (compound 1).2. The fluorous biphase technology has gained more and more attention in recent years because of its convenience in recycling and separation of products from the catalyst. Fluorous biphase technology represents a new phase-separation and immobilization technique. Perfluorinated solvents have limited miscibility with most of organic solvents. Combined with the fact that compounds functionalized with fluorous ponytails of appropriate number, size, and shape often dissolve preferentially in perfluorinated solvent allows the easy recovery and recycling of fluorous catalysts. In the present dissertation, the fluorous biphase technology was applied to the acetylation of alcohol and allylation of aldehyde successfully. It is found that with FC-72 as solvent, the compound 1 possesses very high catalytic activity and can be re-used at lest ten times.3. Organotin oxo cluster-catalyzed carbon-carbon bond-forming reactions were researched. In the tetradistannoxane-catalyzed carbon-carbon bond-forming reactions, the catalytic activity of the tetradistannoxane is approved to be very excellent by the experimental results. Moreover, the experiments of changing the groups attached to the Sn atoms revealed that the catalytic activity is strengthened with the enhancement of electron-withdrawing ability of the group attached to the Sn...