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.