Bis(phosphinoamides) based on sugars for highly enantioselective allylic substitution: inversion of stereocontrol by switching from glucose to mannose

New chiral bis(phosphinoamides) based on glucose 1G and mannose 1M have been prepared. Their Pd complexes catalyze the asymmetric desymmetrization of meso-cyclopenten-2-ene-1,4-diol biscarbamate in high ee’s (up to 97%). Glucose and mannose moieties selectively promote formation of the opposite enantiomers, as a consequence of inverted steric motifs around the metal center.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Benzyl-4,6-O-benzylidene-2,3-deoxy-2,3-diamino-α-d-glucoside-N,N′-bis(2′-diphenylphoshinobenzoyl)C58H50N2O2P2[α]D = +23 (c 1.0, CH2Cl2)

Methyl-4,6-O-benzylidene-2,3-deoxy-2,3-diamino-α-d-mannoside-N,N′-bis(2′-diphenylphoshinobenzoyl)C52H46N2O6P2[α]D = −29 (c 1.0, CH2Cl2)