“…However, the inherent challenge in those methods, particularly for α-unsubstituted arylacetic acids, is the competitive formation of undesired α-keto acids via “over-oxidation”. , In the case of arylacetamides, the α-hydroxylation is accomplished via the α-oxyamination with 2,2,6,6-tetramethylpiperidine- N -oxyl (TEMPO) followed by N–O bond scission by employing (over)stoichiometric reagents or through the formation and subsequent hydrogenation of α-keto acid amides. , Of note, reported benzylic C–H hydroxylation approaches do not apply to α-hydroxylation of arylacetic acids functionalized with several competing benzylic groups due to chemoselectivity issues . Likewise, the α-functionalization of α-amino acid esters via aldimines is also not viable for arylacetic acid synthons …”