A series of CO₂ adducts of α‐carbon alkylated N‐heterocyclic olefins (ANHOs–CO₂) were synthesized and characterized by single‐crystal X‐ray diffraction analysis. The in situ FTIR studies demonstrated that ANHOs–CO₂ adducts showed higher thermal stability than the previously reported α‐carbon nonsubstituted N‐heterocyclic olefins (HNHOs–CO₂) due to the enhancement of the electron‐donating properties. Moreover, ANHOs–CO₂ adducts exhibit higher activity in catalyzing the carboxylative cyclization of CO₂ with propargylic alcohols than HNHOs–CO₂ under the same experimental conditions. Meanwhile, various internal and terminal functionalized propargylic alcohols could be tolerated to obtain the corresponding α‐alkylidene cyclic carbonates in moderate to good yields with high stereoselectivity.

中文翻译：

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α-碳烷基化N-杂环烯烃的CO2加合物：用于CO2化学转化的高活性有机催化剂

合成了一系列α-碳烷基化的N-杂环烯烃（ANHOs–CO ₂）的CO ₂加合物，并通过单晶X射线衍射分析对其进行了表征。现场FTIR研究表明，由于提高了供电子性，ANHOs-CO ₂加合物显示出比以前报道的α-碳非取代N-杂环烯烃（HNHOs-CO ₂）更高的热稳定性。此外，ANHOs-CO ₂加合物在催化CO的carboxylative环化表现出更高的活性₂与炔丙醇比HNHOs-CO ₂在相同的实验条件下 同时，可以容忍各种内部和末端官能化的炔丙醇，以中等到良好的收率和高的立体选择性获得相应的α-亚烷基环状碳酸酯。