Synthesis of Activated Cyclopropanes by MHIRC Strategy: A Facile and Efficient Approach to Spirocyclopropanes Using N-Halosulfon­amides

In this study, a one-pot, three-component reaction of two molecules of indane-1,3-dione with aromatic aldehydes for the synthesis of spirocyclopropylindanediones using poly( N -bromo- N -ethylbenzene-1,3-disulfonamide) (PBBS), N , N , N ′, N ′-tetrabromobenzene-1,3-disulfon­amide (TBBDA), poly( N -chloro- N -ethylbenzene-1,3-disulfonamide) (PCBS), and N , N , N ′, N ′-tetrachlorobenzene-1,3-disulfonamide (TCBDA) as novel reagents has been developed. In addition, an effective and simple domino procedure for the preparation of spirodicyanocyclopropylindanediones from indane-1,3-dione and 2-arylidenemalononitriles is reported. These reactions involve Michael addition, halogenation, and intramolecular ring-closing (MHIRC) reaction sequences.