Organocatalyzed Asymmetric α‐Aminoxylation of Aldehydes and Ketones—An Efficient Access to Enantiomerically Pure α‐Hydroxycarbonyl Compounds, Diols, and Even Amino Alcohols

The magic of no metal : Enantiomerically pure α‐hydroxy aldehydes and ketones as well as diols can be synthesized by a direct ( S )‐proline‐catalyzed asymmetric nitroso‐aldol reaction between the parent carbonyl compound and nitrosobenzene. Further elaboration of the obtained adducts provides useful precursors for diversity‐oriented synthesis. The one‐flask transformation of 3‐phenylpropanal into ( R )‐3‐phenylpropane‐1,2‐diol (98 % ee ) is one example.