The front cover picture illustrates the cascade cyclization of propargylic alcohols with diverse nucleophiles for the construction of heterocyclic compounds via the allenyl carbocation intermediate. In this review, these reactions can be divided into four categories based on the types of nucleophiles, such as C‐nucleophiles, O,S‐nucleophiles, N,P‐nucleophiles, and halo‐nucleophiles. A series of functionalized heterocyclic compounds were constructed under mild reaction conditions. Details can be found in the review by Qiang Xiao and co‐workers (X.‐R. Song, R. Yang, Q. Xiao, Adv. Synth. Catal. 2021, 363, 852–876; DOI: 10.1002/adsc.202001142).

中文翻译：

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封面图片：通过丙炔醇的级联环化合成杂环化合物的最新进展（Adv。Synth。Catal。4/2021）

所述前盖的画面示出了丙炔醇与用于经由所述丙二烯基碳正离子中间体杂环化合物的结构不同的亲核试剂的级联环化。在这篇综述中，根据亲核试剂的类型，这些反应可分为四类，例如C-亲核试剂，O，S-亲核试剂，N，P-亲核试剂和卤代亲核试剂。在温和的反应条件下构建了一系列官能化的杂环化合物。细节可以在小强和同事（X.-R.宋，杨河，肖问，审查发现。进阶合成器CATAL。2021，363，852-876; DOI：10.1002 / ADSC。 202001142）。