Synthesis and Application of Chiral 2-Amido and 1-Phenyl-2-amido Dienes in Diels–Alder Reactions to Access Chiral Cyclic Ketones

The preparation of a focused library of chiral 2-amido and 2-amido-1-phenyl-1,3-dienes from a range of chiral oxazolidinones using palladium-catalysis is reported. This palladium-catalyzed carbon-nitrogen bond-forming reaction provides the corresponding chiral amido-dienes in moderate to excellent yields (12 examples, up to 97%). The resulting chiral amido-dienes are employed as novel dienes in Diels-Alder (DA) reactions (58 examples, up to 93:7 dr, up to 70% yield). A range of chiral cyclic ketones were accessed upon hydrolysis, affording products with high levels of enantioselectivity (up to 92% ee, up to 81% yield).