Tetrahydroquinolines via Stereospecific [3 + 3]-Annulation of Donor–Acceptor Cyclopropanes with Nitrosoarenes

A stereospecific [3 + 3]-annulation of donor–acceptor cyclopropanes with nitrosoarenes under the influence of MgBr2 as a stoichiometric Lewis acid and reagent offers a novel approach to various structurally diverse C-8-brominated tetrahydroquinolines. In these cascades C–C, C–N, and C–Br bonds are formed. The reactions are easy to conduct and proceed under mild conditions, and the products can readily be further functionalized, rendering the method highly valuable.