Direct enantio- and diastereoselective Mannich reactions of malonate and β-keto esters with N-Boc and N-Cbz aldimines catalysed by a bifunctional cinchonine derivative

A highly enantioselective Mannich reaction between malonate esters and N-Boc and N-Cbz aldimines, catalysed by a bifunctional cinchonine derivative, has been developed; extension of this methodology to encompass the use of 2-substituted-1,3-dicarbonyl nucleophiles allows the formation of adjacent stereocentres, one of which is quaternary, in high relative and absolute stereocontrol. © The Royal Society of Chemistry 2006.