Chemoselective Oxidation of Benzyl, Amino, and Propargyl Alcohols to Aldehydes and Ketones under Mild Reaction Conditions

Catalytic oxidation reactions often suffer from drawbacks such as low yields and poor selectivity. Particularly, selective oxidation of alcohols becomes more difficult when a compound contains more than one oxidizable functional group. In order to deliver a methodology that addresses these issues, herein we report an efficient, aerobic, chemoselective and simplified approach to oxidize a broad range of benzyl and propargyl alcohols containing diverse functional groups to their corresponding aldehydes and ketones in excellent yields under mild reaction conditions. Optimal yields were obtained at room temperature using 1 mmol substrate, 10 mol % copper(I) iodide, 10 mol % 4‐dimethylaminopyridine (DMAP), and 1 mol % 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) in acetonitrile, under an oxygen balloon. The catalytic system can be applied even when sensitive and oxidizable groups such as alkynes, amines, and phenols are present; starting materials and products containing such groups were found to be stable under the developed conditions. Chemoselective alcohol oxidation! Catalytic oxidation reactions often suffer from low yields and selectivity. Here we develop a method using copper(I) catalysts to selectively oxidize a wide range of benzyl and propargyl alcohols to their corresponding aldehydes and ketones under mild reaction conditions and with excellent yields. This chemoselective catalytic oxidation scheme can tolerate even sensitive and oxidizable groups such as alkynes, amines, and phenols.