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.