Direct and Enantioselective Aldol Reactions Catalyzed by Chiral Nickel(II) Complexes

A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes is reported. The reaction gives the corresponding O-TIPS-protected anti-aldol adducts in high yields and with remarkable stereocontrol and atom economy. Furthermore, the straightforward removal of the achiral scaffold provides enantiomerically pure intermediates of synthetic interest, which involve precursors for anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives. Theoretical calculations explain the observed high stereocontrol.

Automated summary

A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes was reported. The reaction gives high yields of O-TIPS-protected anti-aldol adducts with remarkable stereocontrol and atom economy. The removal of the achiral scaffold provides enantiomerically pure intermediates with synthetic interest for producing anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives, with theoretical calculations explaining the observed high stereocontrol.