[4+3] Cycloaddition of Donor-Acceptor Cyclopropanes with Amphiphilic Benzodithioloimine as Surrogate for ortho-Bisthioquinone

Donor–acceptor cyclopropanes were reacted with amphiphilic benzodithioloimine to give seven‐membered heterocycles with two sulfur atoms. Formally, this transformation can be regarded as a [4+3] cycloaddition reaction of the three‐membered ring and ortho‐bisthioquinone. The benzodithioloimine serves as a surrogate for this highly reactive diene. The structure of the products was confirmed by X‐ray crystallography. Broad signals in 13C NMR studies suggest that several conformers, slowly interconverting on the NMR timescale, are present at room temperature. Hetero‐[4+3]: Benzodithioloimine bearing two sulfur atoms with strongly amphiphilic character was reacted with donor–acceptor cyclopropanes to give seven‐membered heterocycles in good to excellent yields (see scheme).