Decarboxylative Mannich Reactions with Substituted Malonic Acid Half-Oxyesters.

The decarboxylative Mannich reaction between imines and substituted malonic acids half-oxyesters (SMAHOs) has been developed using 1,4-diazabicyclo[2.2.2]octane (DABCO) as an organocatalyst. The reaction proceeds under simple reaction conditions and tolerates a broad range of substrates, affording general access to β2,3-aminoesters, the syn diastereomer being the major one. An alternative multicomponent protocol has also been developed to increase the overall eco-compatibility of the process.