Air-Induced Cyclization Reaction Of 2-Alkynylphenylphosphine Oxides To Synthesis Benzophospholes Oxides

With dimethylformamide as the solvent,the phosphine in the molecule is induced by the presence of trace air in the formation of phosphine radicals,and with the intramolecular C?C bond generated cyclization addition of benzo[b]phosphole oxides.The reaction is carried out by a free radical mechanism,which is not only simple to operate,atom-economic,high yield,but also does not add transition metal catalysts and other additives.It is noteworthy that this method is environmentally friendly access to benzo[b]phosphole with excellent functional group compatibility.In any case,our reaction provides an effective method for the synthesis of benzo[b]phosphole.