Ludwig-Maximilians-Universität München, Department Chemie Butenandtstrasse 5-13, Haus F, 81377 München (Germany).
Angew Chem Int Ed Engl. 2014 Jul 21;53(30):7933-7. doi: 10.1002/anie.201404221. Epub 2014 Jun 24.
A flow procedure for the metalation of functionalized heterocycles (pyridines, pyrimidines, thiophenes, and thiazoles) and various acrylates using the strong, non-nucleophilic base TMPMgCl⋅LiCl is reported. The flow conditions allow the magnesiations to be performed under more convenient conditions than the comparable batch reactions, which often require cryogenic temperatures and long reaction times. Moreover, the flow reactions are directly scalable without further optimization. Metalation under flow conditions also allows magnesiations that did not produce the desired products under batch conditions, such as the magnesiation of sensitive acrylic derivatives. The magnesiated species are subsequently quenched with various electrophiles, thereby introducing a broad range of functionalities.
本文报道了一种使用强非亲核碱 TMPMgCl·LiCl 实现功能化杂环(吡啶、嘧啶、噻吩和噻唑)和各种丙烯酸酯的金属化的流程方法。与通常需要低温和长时间的可比分批反应相比,流动条件允许在更方便的条件下进行金属化反应。此外,无需进一步优化即可直接扩大流动反应规模。在流动条件下进行金属化还可以实现分批条件下无法得到所需产物的金属化反应,例如敏感的丙烯酸衍生物的金属化反应。随后,用各种亲电试剂猝灭金属化物种,从而引入广泛的官能团。