Halogenation At ?-Position Of ?-Keto Substituted Diarylphosphonate Oxides

?-Keto substituted diarylphosphonic oxide is one of important organophosphorus compounds,which has a wide range of applications in organic synthesis chemistry.In this thesis,the progress of the synthesis of ?-keto diarylphosphonate oxide has been summarized,and the corresponding transformations involved of ?-keto substituted diarylphosphonate oxide has also been briefly introduced.As a continued research interesting in the halogenation of active methyle ne compounds,we have been successfully realized halogenation at ?-position of ?-keto substituted diarylphosphonate oxides using easily available N-chlorosuccinimide(NCS)as the chlorine source in toluene.The reaction features mild reacation conditions,wide substrates scope,good to excellent yields.Notably,when N-bromosuccinimide(NBS)was applied as the bromine source to replace NCS under the same conditions,and the corresponding bromine were also obtained.Moreover,the corresponding asymmetr ic transformation has been investigated and the asymmetric induction was observed.