N-Heterocyclic carbene-catalyzed [4 + 2] cyclization of α,β-unsaturated carboxylic acids bearing γ-H with isatins: an enantioselective synthesis of spirocyclic oxindole–dihydropyranones†,10.1039/C5OB02160J

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Lactoyl-CoA 全氟丁基戊烷白叶藤碱全氟己基辛烷新白叶藤碱壳寡糖特色专题-生物多肽

N-Heterocyclic carbene-catalyzed [4 + 2] cyclization of α,β-unsaturated carboxylic acids bearing γ-H with isatins: an enantioselective synthesis of spirocyclic oxindole–dihydropyranones†

Ling Zhu,Chenxia Yu,Tuanjie Li,Yuhong Wang,Yinan Lu,Wenjing Wang,Changsheng Yao

Organic & Biomolecular Chemistry Pub Date : 12/16/2015 00:00:00 , DOI:10.1039/C5OB02160J

Abstract

An NHC-catalyzed asymmetric [4 + 2] annulation of isatins and α,β-unsaturated carboxylic acids bearing γ-H gave spirocyclic oxindole–dihydropyranones successfully via an in situ activation strategy. This protocol featured easy availability of raw materials, good yields and excellent enantioselectivities (up to 99% ee).