Organocatalytic Asymmetric α-Aminoxylation of Aldehydes

Significance

The asymmetric secondary amine 1 mediated α-aminoxylation of aldehydes is reported. A combination of the newly developed catalyst 1, stoichiometric amounts of TEMPO, and sub­stoichiometric amounts of benzoyl peroxide as the oxidant furnished an array of the desired α-amin­oxy alcohols in high yields and optical purities. The synthetic utility of the products was demonstrated in transformations, such as Pinnick oxidations, ­diastereoselective Grignard additions as well as a one-pot oxidation-aminoxylation of primary alcohols. Furthermore, the latter transformation supports the mechanistic assumptions involving enamine formation, oxoammonium salt addition and hydrolysis.