Sulfonyl-PYBOX/ErCl3 complex enable highly enantioselective synthesis of α,α-dialkyl and α-alkyl-α-aryl hydrazinonitriles (opens in new tab)

We report the highly enantioselective nucleophilic addition reaction of simple ketone-derived hydrazones. Accordingly, a ErCl₃-catalyzed cyanation of both aliphatic and aryl ketone hydrazones is achieved for the facile access of Cα-tetrasubstituted α-hydrazino nitriles in up to 96% ee, by using the sterically confined pyridinebisoxazoline (PYBOX) ligand featuring a sulfonyl group at the pyridine C4 position. This method enables the shortest catalytic enantioselective total synthesis of L-carb...