Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, China.
Nat Commun. 2023 Apr 5;14(1):1883. doi: 10.1038/s41467-023-37538-1.
In canonical organic chemistry textbooks, the widely adopted mechanism for the classic transetherifications between ethers and alcohols starts with the activation of the ether in order to weaken the C-O bond, followed by the nucleophilic attack by the alcohol hydroxy group, resulting in a net C-O/O-H σ-bond metathesis. In this manuscript, our experimental and computational investigation of a ReO mediated ring-closing transetherification challenges the fundamental tenets of the traditional transetherification mechanism. Instead of ether activation, the alternative activation of the hydroxy group followed by nucleophilic attack of ether is realized by commercially available ReO through the formation of perrhenate ester intermediate in hexafluoroisopropanol (HFIP), which results in an unusual C-O/C-O σ-bond metathesis. Due to the preference for the activation of alcohol rather than ether, this intramolecular transetherification reaction is therefore suitable for substrates bearing multiple ether moieties, unparalleled by any previous methods.
在经典的有机化学教科书中，广泛采用的醚和醇之间的经典转醚反应机制从醚的活化开始，以削弱 C-O 键，然后由醇羟基进行亲核攻击，导致净 C-O/O-H σ 键交换。在本文中，我们对 ReO 介导的闭环转醚反应的实验和计算研究挑战了传统转醚反应机制的基本原则。与醚的活化相反，通过在六氟异丙醇 (HFIP) 中形成高铼酸盐酯中间体，商业可得的 ReO 实现了对羟基的替代活化，随后进行醚的亲核攻击，导致不寻常的 C-O/C-O σ 键交换。由于对醇的活化的偏好，因此这种分子内转醚反应适用于带有多个醚部分的底物，这是以前任何方法都无法比拟的。
