Summary: | A total of 24 novel organocatalysts based on (<i>S</i>)-quininamine as a chiral tertiary amine and on enaminone or 1,2-benzenediamine as hydrogen bond donors were synthesized. The enaminone-type catalysts were prepared by the transamination of <i>N</i>,<i>N</i>-dimethyl enaminones with (<i>S</i>)-quininamine (9 examples) and the 1,2-benzenediamine-type catalysts were prepared in 3 steps from (<i>S</i>)-quininamine and <i>ortho</i>-fluoronitrobenzene derivatives (15 examples). Their organocatalytic activity was evaluated in the Michael addition of acetylacetone to <i>trans</i>-β-nitrostyrene. Enantioselectivities of up to 72% <i>ee</i> were observed.
|