Guided by the transition metal hydrogen atom transfer and radical-polar crossover concept, we developed a catalytic, Markovnikov-selective, functional-group tolerant, and scalable synthesis of cyclic carbamates, which are found in the structures of many bioactive compounds. This method not only provides common oxazolidinones but also six-to-eight-membered ring products. The reaction proceeds through the intramolecular displacement of an alkylcobalt(IV) in-termediate and dealkylation by 2,4,6-collidine; the activation energies of these steps were calculated by DFT. Cyclic ureas and cyclic phosphoramidates were also synthesized under the same reaction conditions.

中文翻译：

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氢原子转移和自由基-极性交换催化合成氨基甲酸酯和尿素

在过渡金属氢原子转移和自由基-极性交叉概念的指导下，我们开发了催化氨基甲酸酯选择性，官能团耐受和可扩展的环状氨基甲酸酯合成方法，这些化合物在许多生物活性化合物的结构中均得到发现。该方法不仅提供常见的恶唑烷酮，而且还提供六至八元环产品。反应通过中间体的烷基钴（IV）的分子内置换和2,4,6-可力丁脱烷基而进行。这些步骤的活化能通过DFT计算。在相同的反应条件下也合成了环状脲和环状氨基磷酸酯。