Synthesis And Catalytic Application Of Air-Stable Binuclear Organoantimony Complexes

Antimony has a "wartime metal" reputation as a special mineral, which has wideapplications in organic synthesis, catalysis, biomedicine and other fields.Xikuangshan of Hunan in China has the biggest production of Antimony in the world,so we have a unique advantage in the applications of Antimony. As an importantbranch of Antimony chemistry, Organoantimony has gained rapid developments inrecent years. But the following issues are also increasingly prominent to be solved:（1）organoantimony compounds are sensitive to water, oxygen or other substances, whichbecomes the limitation of its applications;（2） the Lewis acidity of organoantimonycompounds is weak and methods to increase its acidity are limited;（3） there are lessresearch of the relationship between the microscopic structure of the Organoantimonycompounds and their activity in the molecular level.Based on the shortcomings of the structures and applications of organoantimonycompounds, five kinds of binuclear ligand precursors and four kinds oforganoantimony compounds were synthesized, two of which were air-stable andmoisture-tolerant. Then the compunds were examined as catalyst for synthesis ofβ-amino ketones. Some main research results were obtained as follows:1. Five kinds of binuclear ligand precursors were synthesized, using1,4-dibromo-2,5-di （bromomethyl）benzene as starting materials: C₆H₂（CH₂NMe₂）₂Br₂（3）, C₆H₂（CH₂NPh₂）₂Br₂（4）, o-C₆H₂（CH₂OCH₂C₆H₄Br）₂Br₂（9）, p-C₆H₂（CH₂OCH₂C₆H₄Br）₂Br₂（10）, p-C₆H₂（CH₂NCMe₃CH₂C₆H₄Br）₂Br₂（12）. On account of theirsymmetric stucture, chemical stablity, they will play an important part in theapplication of synthesis of organobinulear complexes.2. The binuclear organoanmony complexes C₆H₂（CH₂NMe₂SbPh₂）₂（13）,[C₆H₂（CH₂NHMe₂SbPh₂）₂]²⁺[OSO₂C₈F₁₇]₂^-（14）,[C₆H₂（CH₂NHMe₂SbPh₂）₂]²⁺[ClO4]-2（15）, m-C₆H₂（CH₂OCH₂C₆H₄SbPh）₂（16） were synthesized. Reported forthe first time,14and15were regarded as BLA-type of organoantimony complexeswhich have developed new applications of organoantimony. Their components andphysical properties were characterized by single crystal X-ray diffraction, nuclearmagnetic resonance （NMR）, thermogravimetric analysis （TG-DSC） etc. The resultsshowed the compounds were air-stable and moisture-tolerant. X-ray analysis result confirmed the novel structure of such kind complex had a special cavity, showing agood prospect.3. The organoantimony complexes as catalysts for synthesis of β-amino ketonesshowed excellent catalytic efficiency. β-amino ketones were synthesized in highyield（95.6%） and good stereoselectivity under mild conditions. The amount ofcatalyst is only0.1mol%, which is far less than that of conventional catalysts. What’smore, the self-separation effect of the reaction provided great convenience forpost-treatment. According to the microscopic structure of the catalyst, the relationshipbetween structure and catalytic activity was investigated initiatorily, and the possiblemechanism was proposed.