[3+1+1] annulation of isocyanoacetates with nitrosoarenes for the preparation of 1,4,5‐trisubstituted imidazoles or 4,5‐dihydro‐1H‐imidazoles has been disclosed. Isocyanoacetates serve as both a three‐atom component and a one‐carbon unit in the reaction. Specially, with catalytic amounts of Ag₂CO₃ and a reduced temperature this [3+1+1] annulation of isocyanoacetates enables the formation of trans‐imidazolines in good yield and with high diastereoselectivity. Silver plays a critical dual role: i) as the catalyst for the efficiency to activate the isocyanides and ii) the oxidant in aromatization process.

中文翻译：

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含亚硝基芳烃的银促进的[3 + 1 + 1]异氰基乙酸酯环化

[3 + 1 + 1]异氰酸酯与亚硝基芳烃的环化反应已用于制备1,4,5-三取代的咪唑或4,5-二氢-1 H-咪唑。异氰基乙酸酯在反应中既是三个原子的成分，又是一个碳原子的单元。特别是，在催化量的Ag ₂ CO ₃和降低的温度下，这种[3 + 1 + 1]异氰酸酯环化反应可以形成高收率和高非对映选择性的反式咪唑啉。银起着至关重要的双重作用：i）作为有效活化异氰酸酯的催化剂，ii）芳构化过程中的氧化剂。