Hypervalent Iodine Regants Mediated Amination Of Arenes And Aryl Alkynes

The development of facile and efficient protocols for constructing aromatic C-N bond has captured much attention because the aryl nitrogen functionality exist extensively in numerous biologically active compounds,functional materials and organic synthetic intermediates.The direct functionalization of aromatic C-H bonds for C-N bond formation is of great importance owing to its step and atom-economical advantages.Besides,ynamides and enamidesare two classes of highly functionalized itrogen-contaiming compounds.Ynamides,which can be considered as an important subgroup of alkynes,have been emerged as versatile functionalities and widely utilized in modern organic synthesis.Enamides are another class of powerful synthetic intermediates which find wide applications in various organic synthesis.In this thesis we have developed novel and efficient methods for the preparation of arylamine,ynamides and enamides which might possess significant synthetic application value.The main contents are as follows.1.A remote oxidative C-H bond amidation of anilides with dibenzenesulfonimides mediated by PhI（OAc）₂ under metal-free conditions provided para-amidated anilides with high selectivity and moderate to good yields.The reaction proceeded under mild or neutral conditions and it has good air and moisture tolerance.The method represents a novel and facile strategy for the synthesis of arylamimes（Scheme 1）.Scheme 1 Oxidative C-H Amidation of Anilides2.Divergent reactions between alkynes and dibenzenesulfonimide were reported which can generate useful synthons ynamides and enamides selectively.Oxidative C（sp）-H bond amidation of various arylacetylenes occurred in the presence of a hypervalent iodine reagent to form corresponding ynamides.Without any catalyst or oxidant,direct hydroamidation occurred to produce regioselective Markovnikov’s enamides.Both reactions proceeded under facile,neutral and metal-free conditions and possessed the merit of stable performance and easy operation.It provided novel and eff-icient methods for the preparation of ynamides and enamides.Scheme 2 Selective Synthesis of Ynamides and Enamides.