A mechanism for the thermal instability and selective rearrangement of 2-bromooxazolines is proposed and examined using the highly accurate G4(MP2) thermochemical protocol. We propose this rearrangement to be autocatalyzed by bromide ions that are initially formed via a bimolecular reaction between two 2-bromooxazoline molecules. We find this step to be rate determining, and it results in a consequent and more favorable propagative reaction of bromide ions with the starting material (2-bromooxazoline). The proposed mechanism sheds light on experimental observations and provides a coherent explanation for 2-bromooxazolines thermal instability. We proceed to rationalize the high barrier of the rate-determining step via comparison with experimentally known pathways.

中文翻译：

---

通过高级量子化学方法对 2-溴恶唑啉自催化重排为 2-溴异氰酸酯的机理见解

提出并使用高度准确的 G4(MP2) 热化学协议检查了 2-溴恶唑啉的热不稳定性和选择性重排的机制。我们建议这种重排由最初通过两个 2-溴恶唑啉分子之间的双分子反应形成的溴离子自动催化。我们发现这一步是决定速率的步骤，它会导致溴离子与起始材料（2-溴恶唑啉）发生后续且更有利的传播反应。所提出的机制阐明了实验观察，并为 2-溴恶唑啉的热不稳定性提供了连贯的解释。我们继续通过与实验已知途径的比较来合理化速率决定步骤的高障碍。