A novel N-heterocyclic carbene (NHC)-catalyzed asymmetric [3 + 3] cycloaddition between α-bromoenals and 5-aminoisoxazoles has been developed. With this method, various dihydroisoxazolo[5,4-b]pyridin-6-ones were obtained in high yields (up to 99%) with excellent enantioselectivities (up to >99%) under mild conditions. Notably, this is the first example of direct catalytic asymmetric synthesis of dihydroisoxazolo[5,4-b]pyridin-6-ones.

中文翻译：

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N-杂环卡宾催化直接对映选择性合成二氢异恶唑并[5,4-b]吡啶-6-酮

开发了一种新型 N-杂环卡宾 (NHC) 催化的 α-溴烯醛和 5-氨基异恶唑之间的不对称 [3 + 3] 环加成反应。利用该方法，在温和条件下以高产率（高达 99%）和优异的对映选择性（高达 >99%）获得了各种二氢异恶唑并[5,4 - b ]吡啶-6-酮。值得注意的是，这是直接催化不对称合成二氢异恶唑并[5,4 - b ]吡啶-6-酮的第一个例子。