The Reaction Of Triphenylphosphine With Electron-deficient Alkynes

Ever since the discovery that organophosphorus reagents could be used for functional group transformations, for example, Wittig and Mitsunobu reactions, reagents incorporating phosphanes have played an important role in synthetic chemistry. Their application in organic chemistry has not only been limited to the simple transformation of molecular functionalities, in the past few decades their use has been extended to catalytic carbon-carbon bond forming reactions. The many precursors used to generate reactive dipoles with phosphanes have been generally electron-deficient enones, allenoates, alkynoates, or conjugated dienes.1,3-Dipolar cycloaddition is a convenient synthetic methodology for the construction of cyclic molecular structures in synthetic chemistry. They can react with a variety of electrophilic coupling partners undergoing [2+1]、[2+3]、[2+4]、[3+3]、[3+6] annulations. To date, numerous reports have been published on the synthetic applications of organophosphanes, phosphanes are key reagents in the cyclization step of the synthesis. They can build complex carbocyclic rings, spiro compounds, heterocyclic compounds and condensed ring compounds, which are widely used in the total synthesis of natural products and other fields. In this paper we concentrated our research work on the development of new effective synthetic reactions for the carbocyclic rings.1. Three-component reactions of triphenylphosphine, but-2-ynedioate, and isatylidene malononitrile (ethyl cyanoacetate) in dimethoxyethane resulted in triphenylphosphanylidene spiro[cyclopentane-1,3’-indolines] in satisfactory yields. Furthermore, similar three-component reactions of triphenylphosphine, hex-2-en-4-ynedioate, and isatylidene malononitrile (ethyl cyanoacetate) afforded functionalized spiro[cyclopent[2]ene-1,3’-indolines] in good yields. Twenty derivatives were obtained and were characterized by 1H NMR,13C NMR, IR, HRMS spectroscopy. The single crystal structures of three products were determined by X-ray diffraction method.2. The functionalized cyclopentene derivatives were successfully synthesized in good yields. Three component reactions of triphenylphosphine, hex-2-en-4-ynedioate, and nitroalkenes afforded functionalized cyclopentene derivatives. We have synthesized twelve products, and all of them were characterized by 1H NMR,13C NMR, IR, HRMS spectroscopy. The single crystal structures of two products were determined by X-ray diffraction method.3. This chapter focuses on the synthesis of cephalosporin antibiotics-cefalotin acid and conducted process improvement. Ahrough conditions were optimized to obtain high yield, the process was proposed with high quality products and environmental protection which suitable for industrial production.