Enantioselective Allenylation of Ketimines Derived from Isatins Using Chiral Bis(imidazoline)‐Palladium Catalysts

Abstract

The catalytic enantioselective allenylation of ketimines derived from isatins is described. Products with high regio-and enantioselectivities were obtained in the presence of a bis(imidazoline)palladium catalyst. The obtained products were then converted into various chiral amines. The stereoselectivity origin was revealed by DFT calculations of the transition state.

Accessing unnatural α-amino acids with tetrasubstituted stereogenic centersviacatalytic enantioselective reactions of ketimine-type α-iminoesters/α-iminoamides

“…In 2022, Nakamura and co-workers reported the successful synthesis of α-tetrasubstituted α-allenyl amines, which involved enantioselective allenylation of isatin-derived ketimines 21e (Scheme 57). 89 This reaction is catalyzed by their original chiral bis(imidazoline)-containing palladium pincer complex 144 to afford allenyl adducts 143 with high enantioselectivities. In addition, DFT calculations showed that the most stable transition state leads to ( R )- 143 as the major isomer.…”