Differentiating enantiomers by directional rotation of ions in a mass spectrometer.

Conventional mass spectrometry does not distinguish between enantiomers, or mirror-image isomers. Here we report a technique to break the chiral symmetry and to differentiate enantiomers by inducing directional rotation of chiral gas-phase ions. Dual alternating current excitations were applied to manipulate the motions of trapped ions, including the rotation around the center of mass and macro movement around the center of the trap.

Ligand-Controlled Stereoselective Synthesis of 2-Deoxy-β-C-glycosides by Cobalt Catalysis.

2-Deoxy-β-C-glycosides represent an important class of carbohydrates that are present in many bioactive molecules. However, owing to the lack of substituents at the C2 position, the stereoselective synthesis of 2-deoxy-β-C-glycosides is highly challenging. Herein, we report a ligand-controlled stereoselective C-alkyl glycosylation reaction to access 2-deoxy-β-C-alkyl glycosides from readily available glycals and alkyl halides.

Cobalt-Catalyzed Desymmetric Isomerization of Exocyclic Olefins.

Chiral cyclic olefins, 1-methylcyclohexenes, are versatile building blocks for the synthesis of pharmaceuticals and natural products. Despite the prevalence of these structural motifs, the development of efficient synthetic methods remains an unmet challenge. Herein we report a novel desymmetric isomerization of exocyclic olefins using a series of newly designed chiral cobalt catalysts, which enables a straightforward construction of chiral 1-methylcyclohexenes with diversified functionalities.