Enantioselective construction of oxa- and aza-angular triquinanes through tandem [4 + 1]/[3 + 2] cycloaddition of sulfur ylides and nitroolefins.

A formal [4 + 1]/[3 + 2] cycloaddition sequence of sulfur ylides and alkene-tethered nitroolefins has been developed. The use of (R)-binol-derived chiral sulfide leads to an asymmetric process that allows the construction of oxa- and aza-angular triquinanes in good to excellent diastereo- and enantioselectivities.