Chromium-Catalyzed Cross-Coupling of Methyl Ketones with Cyclic Ketones toward the Selective Synthesis of β-Branched β,γ-Unsaturated Ketones.

Chromium-catalyzed cross-coupling of methyl ketones with cyclic ketones to β-branched β,γ-unsaturated ketones are reported. Interestingly, single-crossed aldol condensation products are formed, even in reactions in which a mixture of products is possible. The reaction is highly chemoselective and regioselective. This catalytic route gives a unique opportunity to integrate the chemistry of the synthetic challenge cross-coupling reaction of ketones and the alkene migration reaction into a reaction pot.