Stereoselective cascade reactions for construction of polyfunctionalised octahydroquinolines via [2C+2C+1C,1N] cyclisation

A conceptually unifying approach for a highly enantio- and diastereoselective synthesis of polyfunctionalised octrahydroquinolines incorporating three contiguous chiral centres is reported. The synthesis involves diphenylprolinol silyl ether-catalysed Michael addition of 1,3-cyclohexanedione to nitroalkenes followed by potassium carbonate-promoted aza-Henry reaction with N-tosyl aldimines, intramolecular hemiaminalisation and dehydration reaction cascade in a one-pot operation.