Copper-Catalyzed Microwave-Expedited Oxyphosphorylation of Alkynes with Diethyl Phosphite and t-Butyl Hydroperoxide Synthesis of Densely Functionalized Phosphonylated Indenones

Treatment of alkynes with diethyl phosphite and t-butyl hydroperoxide in the presence of [Cu(MeCN)(4)]BF4 under microwave irradiation produced the oxyphosphorylation of the triple bond, giving rise to the corresponding beta-ketophosphonates in moderate-to-good yields. When the triple bond was conjugated to a carbonyl group bearing an aromatic ring, it led to the cyclization of the resulting ketone intermediate, producing eventually different phosphonylated indenones.