Scheme 4.
Oxidation of amines (13a-1) in the presence of benzyl alcohol (12a) by 1 to afford imines (16h-q). a Yields are isolated yields of the reaction run on 2.0 mmol scale relative to the benzyl alcohol starting material using 2.0 molar equiv of 1, 1.2 equiv of amine, 3 equiv of p-TsOH, 1 mmol of MgSO4, and 3 equiv of K2CO3 after an extractive work-up.