Palladium‐Catalyzed Cascade Carbonylation to α,β‐Unsaturated Piperidones via Selective Cleavage of Carbon–Carbon Triple Bonds
Yao Ge, Fei Ye, Ji Yang, Anke Spannenberg, Haijun Jiao, Ralf Jackstell, Matthias Beller
Abstract
A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide a broad variety of interesting heterocycles. Key to the success of this transformation is a remarkable catalytic cleavage of the present carbon-carbon triple bond by using a specific catalyst with 2-diphenylphosphinopyridine as ligand and appropriate reaction conditions. Mechanistic studies and control experiments revealed branched unsaturated acid 11 as crucial intermediate.
Topics & Concepts
CarbonylationPalladiumCatalysisReinforced carbon–carbonCascadeChemistryTriple bondCarbon fibersCleavage (geology)Organic chemistryCombinatorial chemistryCarbon monoxideMaterials scienceDouble bondComposite numberChromatographyFracture (geology)Composite materialCatalytic C–H Functionalization MethodsCyclopropane Reaction MechanismsSynthetic Organic Chemistry Methods