Diarylprolinol with Trifluoromethyl Substituents and Diphenylprolinol-Derived Perfluoroalkanesulfonamide as Organocatalysts in the Cross-Aldol Reaction of Aldehydes

The asymmetric cross-aldol reaction of two different aldehydes is a synthetically relevant reaction. Diarylprolinol catalyst with trifluoromethyl substituents and sulfonamide catalyst derived from diphenylprolinol are organocatalysts for the cross-aldol reaction. The reactivity and stereoselectivity of these two catalysts were compared in the asymmetric cross-aldol reactions of propanal and acetaldehyde as nucleophilic aldehydes and several electrophilic aldehydes. Depending on the electrophilic aldehydes, the preferable catalyst differs. By the proper selection of these two catalysts, potentially synthetically useful chiral building blocks can be synthesized with diastereoselectivities of anti:syn=2.6:1 similar to>20:1 and enantioselectivities of 60 similar to>98% ee.

Automated summary

The asymmetric cross-aldol reaction is a synthetically relevant reaction. The reactivity and stereoselectivity of different catalysts were compared for the reaction, and it was found that the proper selection of catalysts can lead to the synthesis of chiral building blocks with high diastereoselectivities and enantioselectivities.