A novel protocol for the construction of highly functionalized 2-(pyridin-3-yl)-chromeno[2,3-d]pyrimidines (PCPMDs) from 3-cyanochromone with 1,1-enediamines via an unprecedented cascade reaction has been developed by simply refluxing a mixture of 3-cyanochromone 1 and various types of 1,1-enediamines 2 under the catalysis of silver carbonate. As a result, a series of PCPMDs 3 were obtained through a novel cascade reaction involving an amazing electrocyclization mechanism of a cyano group with α,β-unsaturated nitriles. This reaction formation of PCPMDs was accompanied by the formation of four bonds and the cleavage of one bond in one step. This protocol can be used for the synthesis of various pyridin-3-yl-substituted complex pyrimidine derivatives, and it is suitable for combinatorial and parallel syntheses of PCPMD drugs or natural-like products.

中文翻译：

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银催化的3-氰基色酮与1,1-二烯胺的级联反应：高度官能化的2-（吡啶-3-基）-铬[2,3-d]嘧啶的合成

通过一种空前的级联反应，由3-氰基色酮与1,1-烯二胺反应构建了高度官能化的2-（吡啶-3-基）-铬[2,3- d ]嘧啶（PCPMDs）。简单地回流3- cyanochromone的混合物1和各种类型的1,1- enediamines 2碳酸银的催化下。结果，一系列PCPMD 3通过新颖的级联反应获得，该级联反应涉及氰基与α，β-不饱和腈的惊人的电环化机理。PCPMD的这种反应形成伴随着四个键的形成和一个键的裂解一步。该方案可用于合成各种由吡啶3-基取代的嘧啶衍生物，并且适用于PCPMD药物或天然产物的组合和平行合成。