No Transition Metals Required – Oxygen Promoted Synthesis of Imines from Primary Alcohols and Amines under Ambient Conditions

The synthesis of imines denotes a cornerstone in organic chemistry. The use of alcohols as renewable substituents for carbonyl-functionality represents an attractive opportunity. Consequently, carbonyl moieties can be in situ generated from alcohols upon transition-metal catalysis under an inert atmosphere. Alternatively, bases can be utilized under aerobic conditions. In this context, we report the synthesis of imines from benzyl alcohols and anilines, promoted by KOtBu under aerobic conditions at room temperature in the absence of any transition-metal catalyst. We present a detailed investigation of the radical mechanism underlying the reaction revealing a complex reaction network, which supports the experimental findings.