A Facile and Rapid Route to Highly Enantiopure 1,2-Diols by Novel Catalytic Asymmetric α-Aminoxylation of Aldehydes

R‐ or S‐configured 1,2‐diol precursors are formed in good yields (54–86 %) and with excellent enantioselectivities (94 to 99 % ee) by using a simple one‐pot sequence—catalytic α‐aminoxylation of aldehydes followed by in situ reduction with NaBH4—with L‐ or D‐proline as the catalyst and nitrosobenzene as the oxygen source (see scheme).