Concise asymmetric synthesis of fully substituted isoxazoline-N-Oxide through lewis base catalyzed nitroalkene activation

摘要

(Figure Presented) Transforming isoxazoline-N-oxides: A concise asymmetric synthesis of isoxazoline-N-oxides is reported through secondary amine Lewis base catalyzed nitroalkene activation and sequential intermolecular condensation with aldehydes and ylides. Application of camphor-derived chiral sulfur ylides gave the enantiomeric-enriched isoxazolineN-oxides in excellent yields and stereoselectivity. Simple transformations of isoxazoline-N-oxide led to the gramscale synthesis of a (-)-clausenamide analogue in four steps, with excellent stereochemistry control (see scheme).