A catalytic asymmetric 1,3-dipolar cycloaddition reaction of a nitrone possessing diisopropyl amide moiety to γ-substituted allylic alcohols was achieved by using diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the corresponding 3,4,5-trisubstituted isoxazolidines with excellent enantioselectivity up to over 99% ee.
enantioselective 1,3-dipolar cycloaddition of nitrones bearing an amide moiety to allylalcohol has been realized by using a catalytic amount of diisopropyl (R,R)-tartrate as a chiral auxiliary. Addition of amine N-oxide such as pyridine N-oxide, was crucial to realize a reproducible excellent enantioselectivity up to 98% ee.
通过使用催化量的酒石酸二异丙酯作为手性助剂,实现了带有酰胺部分的硝酮与烯丙醇的高度非对映选择性和对映选择性 1,3-偶极环加成反应。添加胺 N-氧化物(如吡啶 N-氧化物)对于实现高达 98% ee 的可重现的优异对映选择性至关重要。