Asymmetric Cyanation of α-Ketimino Ester Derivatives with Chiral Ru–Li Combined Catalysts
Taiga Yurino, Zhen Wu, Kazuaki Suzuki, Rino Nitta, Yusuke Sakaguchi, Takeshi Ohkuma
Abstract
Asymmetric cyanation of α-ketimino esters catalyzed by combined systems of amino acid/BINAP derivative/Ru(II) complexes and lithium compounds was examined. The use of an appropriate combination of amino acid and BINAP ligands achieved high enantioselectivity for a variety of α-alkynyl (Val/XylBINAP/Ru), α-alkenyl (Val/TolBINAP/Ru), and α-aryl imino esters (Val/XylBINAP/Ru) as well as an isatin-derived cyclic imino amide ( t -Leu/BINAP/Ru) to afford the α-cyano-α-amino esters and the amide with an α-nitrogen-substituted quaternary chiral center with up to 98% ee.
Topics & Concepts
CyanationChemistryBINAPAmideCatalysisAcetylideLithium (medication)ArylMedicinal chemistryNitrileAmino acidStereochemistryEnantioselective synthesisOrganic chemistryEndocrinologyMedicineAlkylBiochemistryCatalytic C–H Functionalization MethodsSynthetic Organic Chemistry MethodsSynthesis and Catalytic Reactions