Concise Asymmetric Synthesis of Fully Substituted Isoxazoline-N-Oxide through Lewis Base Catalyzed Nitroalkene Activation
作者:Cheng Zhong、Lekh Nath S. Gautam、Jeffrey L. Petersen、Novruz G. Akhmedov、Xiaodong Shi
DOI:10.1002/chem.201001237
日期:2010.8.2
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 isoxazoline‐N‐oxides in excellent yields and stereoselectivity. Simple transformations
异恶唑啉N氧化物的转化:据报道,通过仲胺Lewis碱催化的硝基烯烃活化以及与醛和酰基化物的分子间缩合,简明地合成了异恶唑啉N氧化物。樟脑衍生的手性硫基化物的应用可得到对映异构体富集的异恶唑啉N-氧化物,具有出色的收率和立体选择性。异恶唑啉-N-氧化物的简单转化导致在四个步骤中以克级合成(-)-clausenamide类似物,并具有出色的立体化学控制(请参见方案)。