2-Phenylindoles, as a special subset of indole compounds, stand out as some of the most promising candidates for drug development. To guide researchers toward developing new 2-phenylindole drugs in a more environmentally friendly and cost-effective manner, we have summarized and analyzed synthesis methods for 2-phenylindole over the past two decades. Our key findings are as follows: First, among the two methods discussed in this paper, the one-step method is often suitable for the synthesis of 2-phenylindole derivatives with a small amount of substitutions on both sides, whereas the indole C-2 coupling reaction is preferable for indole or C-2 benzene rings with more complex substitutions. Second, the primary challenge in synthesizing 2-phenylindole compounds lies in achieving selectivity at the indole C-2 and C-3 sites. Lastly, to achieve more efficient, economical, and environmentally friendly methods, researchers have developed new catalytic systems, including nontoxic catalysts, metal-free catalysts, recyclable metal catalysts, or nanocrystallized transition metals, as well as new methodologies such as photoinduced reactions, electrocatalytic reactions, magnetocatalytic methods, and aqueous-phase catalytic methods. These avenues may represent future research directions for chemists. In conclusion, there remains ample room for research and development in the green synthesis of 2-phenylindole derivatives.

中文翻译：

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绿色合成具有药理意义的2-苯基吲哚衍生物的合成方法综合分析


2-苯基吲哚作为吲哚化合物的一个特殊子集，是最有前途的药物开发候选药物之一。为了指导研究人员以更环保、更经济的方式开发新的2-苯基吲哚药物，我们对过去二十年的2-苯基吲哚合成方法进行了总结和分析。我们的主要发现如下：首先，在本文讨论的两种方法中，一步法通常适合合成两侧都有少量取代基的2-苯基吲哚衍生物，而吲哚C-2偶联反应对于吲哚或具有更复杂取代基的C-2苯环是优选的。其次，合成2-苯基吲哚化合物的主要挑战在于实现吲哚C-2和C-3位点的选择性。最后，为了实现更高效、经济、环保的方法，研究人员开发了新的催化体系，包括无毒催化剂、无金属催化剂、可回收金属催化剂或纳米晶过渡金属，以及光诱导反应、电催化反应等新方法。反应、磁催化方法和水相催化方法。这些途径可能代表化学家未来的研究方向。综上所述，2-苯基吲哚衍生物的绿色合成还有很大的研发空间。