Department of Chemistry, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad-826004, India.
Chem Commun (Camb). 2021 May 27;57(43):5235-5249. doi: 10.1039/d1cc01265g.
Transition-metal based carbon-heteroatom (C-X) bond formation has attracted the attention of synthetic chemists over the past few years because the resultant aryl/heteroaryl motifs are important substructures in many natural products, pharmaceuticals, etc. Several efficient protocols such as Buchwald-Hartwig amination, Ullmann coupling, Chan-Lam coupling and metal-free approaches have proved beneficial in C-X bond formation. Selective arylation of one hetero-centre over other centres without protection/deprotection thus allowing minimum synthetic manipulation has been achieved for several substrates using these protocols. Azoles are one such novel five-membered heterocyclic core with huge pharmaceutical applications. Though N-arylation on azole-bearing analogues has been extensively practised, selective N-arylation either on one N-centre or the exocyclic N-site of the azole ring in competition with other hetero-centres in the framework has been recently explored for azole-carrying systems. Thus, this review would focus on recent advances in chemo- and regio-selective N-arylation (either on one N-centre or the exocyclic N-site of the azole ring) on azole-containing frameworks.
过渡金属催化的碳-杂原子（C-X）键形成在过去几年中引起了合成化学家的关注，因为所得的芳基/杂芳基结构是许多天然产物、药物等中的重要亚结构。几种有效的方法，如 Buchwald-Hartwig 胺化、Ullmann 偶联、Chan-Lam 偶联和无金属方法，已被证明在 C-X 键形成中是有益的。使用这些方案，对于几种底物，可以在不进行保护/脱保护的情况下，选择性地对一个杂原子中心进行芳基化，而不对其他中心进行芳基化，从而实现最小的合成操作。唑类是一种具有巨大药物应用前景的新型五元杂环核心。尽管唑类化合物的 N-芳基化已经得到了广泛的研究，但最近人们对唑类化合物的 N-芳基化选择性（无论是在一个 N-中心还是在唑环的外环 N-位）进行了研究，以与框架中的其他杂原子中心竞争。因此，这篇综述将重点介绍含唑框架的化学和区域选择性 N-芳基化（在一个 N-中心或唑环的外环 N-位）的最新进展。
