The multicatalytic generation of 3,5,6-trisubstituted 3,4-dihydropyranones with high enantioselectivity using a highly convergent strategy starting from commercially available precursors is reported. The operationally simple three-step, one-pot protocol merges H-bond and NHC catalysis to provide crucial, reactive β-unsubstituted enones from nitroalkenes as latent 1,2-biselectrophiles. These intermediates are directly funneled into a further NHC-catalyzed formal hetero-Diels–Alder reaction to deliver manifold chiral C(4)-unsubstituted dihydropyranones (typical ee >98%), allowing aliphatic and heteroaromatic substituents and hence expanding the scope of this Michael addition/lactonization.

中文翻译：

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一个ñ N-杂环卡宾介导的，对映选择性和Multicatalytic策略访问Dihydropyranones在连续三组分一锅反应

据报道，从市场上可买到的前体开始，采用高度收敛的策略，以高对映选择性多催化生成3,5,6-三取代的3,4-二氢吡喃酮。该操作简单的三步一锅操作方案将H键和NHC催化合并，从硝基烯烃中作为潜在的1,2-双亲电子试剂提供了关键的，反应性的β-未取代的烯酮。这些中间体直接漏斗到进一步的NHC催化的正式杂Diels-Alder反应中，以提供多种手性C（4）-未取代的二氢吡喃酮（典型ee > 98％），允许脂族和杂芳族取代基，因此扩大了该迈克尔加成/内酯化。