Catalytic Asymmetric Retro-Aldol Reaction

Significance

Luo, Cheng, and co-workers report the use of the primary chiral amine catalyst 2 in the highly enantioselective retro-aldol reaction. This process results in a kinetic resolution of racemic aldols 1 with excellent selectivity factors. In cases of sluggish conversion (e.g., to product 1d) the authors found that the resolution could be driven forward by an in situ transfer aldol reaction of the generated aldehyde 4 with acetone. Using this method the authors were able to dramatically improve the reaction rates (and hence the enantiomeric excess of the product), while generating an additional aldol product 5 with the opposite configuration in the same process.