Zn-Catalyzed Diastereo- and Enantioselective Dearomative [3+2] Cycloaddition Reaction of 2-Nitroindoles and 2-Nitrobenzothiophenes

An efficient asymmetric dearomative [3+2] cycloaddition reaction of 2-nitroindoles and 2-nitrobenzothiophenes with 3-isothiocyanato oxindoles was developed by using a chiral Zn(OTf)(2)/bis(oxazoline) complex as a catalyst. With the developed protocol, a range of enantioenriched complex heterocyclic compounds containing three contiguous stereocenters, one of which is spirocyclic center, could be obtained in quantitative yields with excellent diastereo- and enantioselectivities. The potential utility of this method was showcased by the diverse transformations of the products.