A recyclable chiral auxiliary for the asymmetric syntheses of α-aminonitriles and α-aminophosphinic derivatives

Optically active α-aminonitriles and α-aminophosphinic derivatives have been prepared in high yield and high ee using an easy route by extending our previously developed method involving the following sequence: (i) stereoselective Strecker condensation of a chiral ketone with HCN and NH3 followed by (ii) condensation with RCHO, an HCN donor or a phosphinate and (iii) regioselective decomposition of the intermediate to release the target compound. The third step enables the easy regeneration of the initial chiral ketonic auxiliary.

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Ethyl{[(1R,2R,3R,5R)-1,3-dicyano-5-(1-hydroxy-1-methylethyl)-2-methylcyclohexylamino]-phenyl-(S)-methyl}-(R)-phenylphosphinateC27H34N3O3P[α]D20=-30.6 (c 0.01, CH3OH)Absolute configuration: (1R,2R,3R,5R)