Enantiodivergent Reaction of Ketimines with Malononitriles Using Single Cinchona Alkaloid Sulfonamide Catalysts
Shuichi Nakamura, Natsuki Matsumoto, Masato Kibe, Kazuki Abe, Tsunayoshi Takehara, Takeyuki Suzuki
Abstract
Abstract We report the enantiodivergent reaction of ketimines derived from α‐ketoesters with malononitriles using a single chiral source. The reactions using an 8‐quinolinesulfonyl cinchona alkaloid catalyst in the presence and absence of Et 2 Zn gave both enantiomers in high yields with high enantioselectivities (53∼99% yield, 99:1∼3:97 er). The obtained malononitrile‐derived α‐amino acids were converted into various optically active compounds. A reaction mechanism is proposed to explain the observed enantiodivergency. magnified image
Topics & Concepts
CinchonaMalononitrileChemistryEnantiomerCatalysisSulfonamideYield (engineering)Organic chemistryAlkaloidCinchona AlkaloidsOrganocatalysisEnantioselective synthesisCombinatorial chemistryMedicinal chemistryMetallurgyMaterials scienceSynthesis and Catalytic ReactionsAsymmetric Synthesis and CatalysisChemical Synthesis and Analysis