Abstract

Cinchonine-catalyzed simple, expeditious, and efficient protocol for the synthesis of quinoline-based 4H-pyran and tetrahydro-4H-chromenes has been demonstrated via one-pot domino Knoevenagel–Michael cyclocondensation reaction of aromatic aldehyde, active methylene compound and activated C–H acids like alkylacetoacetates/dimedone in ethanol under reflux. This protocol enables a rapid construction of diverse range of 4H-pyran and tetrahydro-4H-chromene derivatives from readily available starting materials. Short reaction time, mild reaction conditions, broad substrate scope, high yields, metal-free approach, and purification without column chromatography are notable features of this methodology.

Graphic abstract

中文翻译：

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辛可宁驱动的多米诺骨牌Knoevenagel–Michael策略：喹啉基4 H-吡喃和四氢4 H-色烯衍生物的无金属合成

摘要

通过一锅多米诺骨牌Knoevenagel-Michael芳香醛，活性亚甲基化合物的活化和活化反应，已证明辛可宁催化简单，快速和有效的合成喹啉基4 H-吡喃和四氢4 H-色烯的方法C–H酸（如乙醇中的乙酰乙酸烷基酯/二甲酮）在回流下。该方案能够从容易获得的原料中快速构建各种范围的4 H-吡喃和四氢4 H-色烯衍生物。反应时间短，反应条件温和，底物范围广，产率高，无金属方法和无需柱色谱法纯化是该方法的显着特征。

图形摘要