Highly selective copper‐catalyzed oxidation of benzyl alcohols to aromatic aldehydes in water at room temperature

Water‐soluble 2N2O–Cu(II) complexes were synthesized and used for the catalytic oxidation of benzylic alcohols to the corresponding aldehydes in pure water resulting in high yields of up to 94%. Importantly, the catalytic system exhibits a wide substrate scope, high functional group tolerance and can be reused directly for subsequent reaction cycles. Using this catalytic system, the product 4‐methylbenzaldehyde can be produced on a multi‐gram scale and in the complete absence of any organic solvent, surfactant or phase transfer reagent. Copyright © 2016 John Wiley & Sons, Ltd.