Organocatalytic enantioselective construction of nitrocyclohexanes containing multiple chiral centres via a cascade reaction†
The stereoselective construction of complex molecules with multiple stereogenicity in a single step represents an extremely useful, but challenging approach to complexity in chemical synthesis. The development of organocatalytic cascade processes has proven useful in these studies, but reports where four or more stereocentres are created in a single step from just two achiral reagents are rare. Herein we report the development of a novel asymmetric domino Michael-Michael reaction between nitrohex-4-enoates and nitro-olefins to generate cyclohexanes of high complexity, including one with a quaternary centre, and three with five contiguous stereocentres. This methodology provides access to a range of useful nitrocyclohexane derivatives, including a novel class of α-lycorane-like structures.