Synthesis And Reactivity Of Main Group Element Derivatives Of O-Carborane

At present carborane chemistry is a very active research field. Great development hasbeen made on the synthesis, structure and chemical reactivity of carborane compounds sincethe first open reports in the1960s. Therefore the synthesis and properties of functionalcarborane compounds become an interesting research direction because of their potentialapplications in biomedical, catalysis, functional materials and many other fields.In this thesis the reactions of the dilithio-dicarba-closo-dodecaborane Li2C2B10H10with1-bromo-3-chloropropane,1-bromobutane, gallium trichloride and indium trichloride,respectively, were studied. The CuCl-mediated one-pot synthesis of C-alkynyl-o-carboranederivatives involving o-carborane (C2B10H12), terminal alkynes and n-butyllithium wasdeveloped. The copper(I)-mediated homocoupling reaction of o-carboranyllithium led to1,1’-bis(o-carborane), and the reaction of its lithium salt with chlorodiphenylphosphine wasstudied.There are six sections in this thesis which are as follows:In chapter1, an introduction to the current status of the research on o-carborane and1,1’-bis(o-carborane) and their derivatives is given, as well as the purposes of this thesis.In chapter2, the reactions of dilithio-o-carborane Li2C2B10H10with1-bromo-3-chloropropane under different conditions are described. The three products1,2-(1,3-propanediyl)-o-carborane (1),1-(ClCH2CH2CH2)C2B10H11(2) and1,2-(ClCH2CH2CH2)2-C2B10H10(3) were isolated and characterized by means of IR and NMR spectroscopy andmass spectrometry, as well as single-crystal X-ray diffraction analyses. Whereas theCuCl-mediated reaction of dilithio-o-carborane with ClCH2CH2CH2Br resulted in compound3and the formation of small amount of1,1’-bis(o-carborane).In chapter3, during the preparation of1,1’-bis(o-carborane) by the homocoupling ofdilithio-o-carborane according to the literature method, the unexpected compounds1-butyl-o-carborane (4) and1,2-dibutyl-o-carborane (5) were also obtained as minor products,their structures were characterized by means of IR, NMR, MS and single-crystal X-raydiffraction (5). The reaction of1,1’-dilithio-bis(o-carborane) with chlorodiphenylphosphinewere studied, the two novel products6and7b were obtained in which the skeletal structrues closo-C2B10have greatly changed, the structural characterization of6and7b were carried outby means of NMR, MS and single-crystal X-ray diffraction.In chapter4, the one-pot synthesis of C-alkynyl-o-carboranes derivatives8a-c byCuCl-mediated cross-coupling reaction of o-carboranyllithium with alkynyllithium wasdescribed, and the characterization of the products were carried out by means of IR, NMR andMS. The mechanism for the formation of carboranes4,5and8a-c is discussed.In chapter5, the reaction of the dilithio-o-carborane with gallium trichloride and indiumtrichloride, respectively, were tried. The reactions were monitored by11B NMR, and somepreliminary results were obtained. The crystals of the o-carboranylgallium compound10wereobtained and the structure was preliminary determined by single-crystal X-ray diffraction.In chapter6, the research content of this thesis is summarized, and a preliminary outlook isgiven for the future work.