| Summary: | A novel methodology for the synthesis of highly substituted pyridines based on the palladium-catalyzed enolate α-alkenylation of ketones is presented; the formation of aromatic compounds is a new direction for this catalytic C-C bond forming reaction. In the key step, a protected β-haloalkenylaldehyde participates in α-alkenylation with a ketone to afford a 1,5-dicarbonyl surrogate, which then undergoes cyclization/double elimination to the corresponding pyridine product, all in one pot. The β-haloalkenylaldehyde starting materials can be obtained from the corresponding methylene ketone via Vilsmeier haloformylation. Using this concise route, a variety of highly substituted pyridines were synthesized in three steps from commercially available compounds.
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