Accessing Grignard Reluctant Aldehyde in 2-Oxoaldehyde by Organocuprates to Give [1,2] Addition and Oxidative Coupling Reactions.

Novel finding of aldehyde in 2-oxoaldehyde (2OA) is presented as it unprecedentedly disinclines to react with Grignard reagents but reacts with moderate organocuprate reagents in anaerobic condition to give [1,2] addition (α-hydroxyketones) reaction. In the presence of air, the reaction produces an efficient protocol for the synthesis of 1,2-diones through a copper-catalyzed oxidative cross-coupling reaction at room temperature. Mechanistic studies indicate that α-hydroxy ketone perhaps is generated before the hydrolysis step/acid work-up process. The α-keto group of 2OA causes to exhibit this peculiar aldehyde behavior toward these organometallic reagents.