An enantioselective 1,3-dipolar cycloaddition of 2-cyclo-hexene-1-one and azomethine ylide generated in situ from isatin and amino ester was developed by employing proline sulfonamide as the catalyst. Consequently, novel polycyclic spirooxindole scaffolds with three contiguous stereocenters were prepared in high yield (up to 95%) with excellent diastereo- (> 20:1 dr) and...
The development of a proline sulphonamide-catalysed method for enantioselective and diastereoselective construction of functionalized cyclohexenones is described. Impact of catalyst structure as well as solvent effects and additives are explored. A significant substrate scope is demonstrated by variation of both the aldehyde and the enone components. Diastereoselective derivatization of the...