Reaction of Active Methylene Groups with 1,2‐Di(Bromoseleno)Benzene toward Benzo‐1,3(2H)‐Diselenoles

Abstract The 1,2‐di(bromoseleno)benzene has been found to be a bifunctional electrophile able to react with C‐H acids. The tandem diselenylation of the active methylene group in β‐diketones, β‐keto‐ and β‐cyanoesters, diethyl malonate, and malonitrile resulted in the ring closure on the carbon atom. Based on this reaction, 2,2‐disubstituted benzo‐1,3(2H)‐diselenoles, a new group of selenaheterocycles, were obtained in good yields.