Facile Domino Access to Chiral Mono-, Bi-, and Tricyclic 2,3-Dihydrofurans

The asymmetric domino Michael-S(N)2 reaction of various 1,3-dicarbonyl compounds to alpha-bromonitroalkenes is described for the first time, employing readily available cinchona-derived bifunctional thioureas as organocatalysts. The novel transformations were highly regio-, chemo-, diastereo-, and enantioselective, which simultaneously gave the chiral tricyclic 2,3-dihydrofurans, bicyclic 2,3-dihydrofurans, and tetrasubstituted 2,3-dihydrofurans with two vicinal chiral carbon centers.