Department of Chemical Engineering and Food Science, Hubei University of Arts and Science, 296 Longzhong Road, Xiangyang 441053, P. R. China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, P. R. China.
J Org Chem. 2021 Aug 6;86(15):10288-10302. doi: 10.1021/acs.joc.1c01019. Epub 2021 Jul 21.
2-Aminobenzothiazoles comprise a valuable structural motif, which prevails in versatile natural products and biologically active compounds. Herein, a switchable and scalable C-N coupling protocol was developed for the synthesis of these compounds from 2-chlorobenzothiazoles and primary amines. Gratifyingly, this protocol was achieved under transition-metal-free and solvent-free conditions. Moreover, introducing an appropriate amount of NaH completely switched the selectivity from mono- toward di-heteroarylation, and further investigations provided a rationale for this new finding. Furthermore, gram-scale synthesis of representative products and was realized by applying operationally simple and glovebox-free procedures, which revealed the practical usefulness of this work. Finally, evaluation of the quantitative green metrics provided evidence that our protocol was superior over the literature ones in terms of green chemistry and sustainability.
2-氨基苯并噻唑是一种有价值的结构基序，广泛存在于各种天然产物和生物活性化合物中。本文开发了一种可切换和可扩展的 C-N 偶联协议，用于从 2-氯苯并噻唑和伯胺合成这些化合物。令人高兴的是，该协议在无过渡金属和无溶剂条件下实现。此外，引入适量的 NaH 可完全将选择性从单杂芳基化切换为二杂芳基化，进一步的研究为这一新发现提供了依据。此外，通过应用操作简单且无需手套箱的程序，实现了代表性产物 和 的克级规模合成，这证明了这项工作的实际用途。最后，定量绿色指标的评估表明，就绿色化学和可持续性而言，我们的方案优于文献中的方案。
