The Synthesis Of Ortho-Cyanated Diarylmethane And The Tertiary Alkylation Of ?,?-dibromoalkenes

Diarymethane derivatives are useful building blocks for organic synthesis.They are widely used in pharmaceuticals,dye precurors and supramolecules.Therefore,the development of an efficient alternative method for the synthesis of diarylmethanes has attracted a great deal of attention.Aromatic nitriles are useful intermediates since they can be easily transformed into a diverse class of functionalities.The cleavage and functionazation of carbon-fluorine bonds have been a challenging topic in modern organic chemistry.The main contents in this thesis are as follows:1)Synthesis of or/tho-cyanated diarylmethanes by the cleavage and cyanation of carbon-fluorine bond of fluoroarenes in the presence of LDA;2)Tertiary alkylation of 3,?-dibromoalkenes.Forty-nine total target compounds were synthesized.In the second chapter,we have developed a rapid and practical method for the synthesis of ortho-cyanated diarymethanes from various readily available fluoroarenes and arylacetonitriles in the presence of LDA at room temperature.Then we extended this protocol to a variety of chloroarenes and bromoarenes.Both chloroarenes and bromoarenes could react with arylacetonitriles smoothly to provide ortho-cyanated diarylmethanes in good yields.And we also proposed a plausible mechanism.Thirty-one novel ortho-cyanated diarylmethanes were synthesized.In the third chapter,we have developed two new methods for the the tertiary alkylation of?,?-dibromoalkenes with tert-butylmagnesium chloride in the presence of 50 mol%CuCN or under metal-free conditions.