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

Organic phosphorus chemistry occupies a significant position in the field of chemistry and chemical industry.Phosphorus-containing heterocycles have wide applications in biochemistry,coordination chemistry,organic synthesis and homogeneous catalysis.Among them,benzo[6] phospholes have inherent optical properties and good application prospects in the field of organic photoelectric materials.At present,there are few related literature reports about the synthetic method of this kind of compounds.Therefore,developing a new method of constructing benzo[6]phospholes derivatives is of great meaningful.In addition,the known types of such structures is rare,expanding new classes of them is of great importance.In this paper,three new methods for the construction of multifunctional substituted benzophosphorene derivatives were revealed.The main contents are as follows:Part 1: A new method for constructing benzo[&]phospholes with active hydroxyl groups using diaryi(arylethynyl)phosphine derivatives and alcohols as raw materials was developed(the first method).The azodiisobutyronitrile(AIBN)was used as the radical initiator to afford carbon radicals of alcohols which followed by addition/cyclization with diaryl(arylethynyl)phosphine oxides,affording a genera]approach to construct a new class of hydroxymethyl benzo[Z?]phosphole oxides.This method has some advantages of mild reaction conditions,simple operation and readily accessible raw materials and catalysts.In addition,no transition metal is involved in the reaction process,which can effectively avoid metal ions residue in the target compounds.The target compounds bear an active hydroxyl functional group,which can be transformed furtherly.Part 2: Based on the above method,a new method for constructing our-ring coplanar benzo[Z?Jphospholes using simple alcohols and diaryl(arylethynyl)phosphine oxides as raw materials by ltone-pof,method was developed.Benzo[6]phospholes with active hydroxyl functional group were generated and catalyzed by AIBN/TBHP using simple alcohols as tlie raw materials,followed by generating larger conjugated benzo[&]phosphole oxides via intramolecular Friedel-Crafts alkylation of hydroxymethyl benzo[Z?]phospholes in the presence of acid.This method is highly efficient and convenient,the intermediates generated in the reaction process do not need to be separated,and metal-free catalyst participates in the reaction.By this method,larger conjugated benzo[6]phosphole oxides could be synthesized,which expanded the classes of such compounds.Part 3: Based on the first method,a new method for constructing benzo[Z?]phospholes containing silicon using silicon compounds reacting with diaryl(arylethynyl)phosphine oxides was developed.The silicon radical was formed by DTBP,and then that silicon radical reacted with diaryl(arylethynyl)phosphine oxides to construct the benzo[Z?]phosphole oxides containing silicon.By this method,various benzo[6]phosphole oxides with silicon could be sythesizd by simple one-step reaction,enriching the types of these compounds.Moreover,compared with the known method,ethyl acetate was used as solvent in this method which is cheap,convenient to get and environmental protection.