Study On New Methods For The Synthesis Of Benzo[b]phosphole Oxides

Phosphorus-containing heterocycles have wide applications in organic synthesis,medicinal chemistry,and material industries.Among these compounds,the phosphorous analogue of nitrogen heterocyclic indole,benzo[b]phospholes have become indispensable organic conjugated heterocyclic system and huge potential in the field of organic photoelectric materials because of their inherent physical and optical properties,which allow the development of new classes of optoelectrochemical materials.However,the known synthetic methods of such compounds is limited at present.Therefore,the development of new,efficient methods for the synthesis of benzo[b]phosphole oxides would be highly appealing and essential.In this paper,we developed two new methods to synthesize benzo[b]phosphole oxides.The main contents are as follows:Part 1:Developed the first cheap efficient,K2S2O8-mediated metal-free phosphorus free radicals addition/cyclization of diarylphosphine oxides with various unactivated alkynes,building a variety of benzo[b]phosphole oxides.The present protocol is mild reaction conditions,simple operation.also innovatively employs metal-free catalyst instead of noble metal catalysts to eliminate any possibility that residual heavy metal in the product.Part 2:Developed the simple and efficient CuBr-DTBP co-catalyzed carbon free radical addition/cyclization of cycloalkanes with diaryl(arylethynyl)phosphine oxides,furnishing rapid access to a structurally diverse array of benzo[b]phosphole oxides.It greatly expand the diversity of such compounds.In addition,compared with extant methods,this methodis more economic,practical,feasible.