Synthesis of 1,2,3,4−Tetrasubstituted Naphthalenesvia a aryl C−P Bond and a C−H Bond Cleavages

• Main Authors: Chien-chuan Shih, 施建全
• Other Authors: Yao-ting Wu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/50246964861466319583

碩士 === 國立成功大學 === 化學系碩博士班 === 95 === 1,2,3,4-Tetraphenylnaphthalene (33a) can be prepared from the reaction of triphenylphosphine and diphenylacetylene (31a) in the presence of the palladium catalyst. The catalytic efficiencies of several palladium complexes, the reactivity of phenylphosphine compounds and the contributions from solvents and additives have been examined. The reaction conditions have been optimized: When the solution of triphenylphosphine and 31a in acetonitrile was added to our developed catalytic system by a syringe pump at 110 ℃, and 33a could be obtained in 62% yield. To our best knowledge, this is the first example for the preparation of naphthalenes via the activation of a phenyl C-P bonds and C-H bonds. Based on this synthetic method, five naphthalene derivatives have been prepared in 22-62% yields. 5,8-Dimethyl-1,2,3,4-tetraphenylnaphthalene (35a) can be accessible directly from p-xylene and 31a under the catalysis of palladium acetate. This protocol provides three obvious advantages: simple, clean and atomic economics. From the structure of 35, an arene offers a〝benzo〞unit to construct a naphthalene core via double aryl C-H activations. Our coworker has optimized the reaction conditions. Based on the procedure, four highly substituted naphthalenes 35ab, 35ac, 35bb and 35cc have been prepared in 22-45% yields.