Deaminative Addition of Alkylpyridinium Salt to Aldehyde

Here we show that a primary amine can engage in the nucleophilic addition to an aldehyde to synthesize an alcohol following preactivation of the amine. The enabling reagent for this radical-polar crossover process is CrCl₂. This reaction is selective for aldehydes and compatible with numerous functional groups, which are not tolerated under classical Grignard-type conditions. Complementary to the well-established imine synthesis, this deaminative alcohol synthesis can broadly expand the chemical space constructed by aldehydes and amines.