Elemental sulfur‐promoted cyclization for the one‐pot synthesis of tetra‐substituted imidazoles from benzylamines and ketones is described. Elemental sulfur combined with molecular oxygen as the benign co‐oxidant was found to be the key for the high efficiency of this transformation under metal‐free conditions. A range of tetrasubstituted imidazoles were synthesized from simple ketones and amines with good functional group tolerance.

中文翻译：

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元素硫促进的酮和脂肪胺的需氧环化反应，用于合成四取代的咪唑

描述了元素硫促进的环化反应，用于由苄胺和酮一锅合成四取代的咪唑。发现元素硫与分子氧结合作为良性助氧化剂是在无金属条件下高效转化的关键。由简单的酮和具有良好官能团耐受性的胺合成了一系列四取代的咪唑。