The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.

中文翻译：

---

金催化的氯炔烃和未活化烯烃之间的 [2+2] 环加成反应

[2+2] 环加成是合成具有高合成价值的应变环丁烯的通用策略。在这项研究中，在金催化下实现了两种不同类型的氯炔烃和未活化烯烃之间的两种有效的分子间 [2+2] 环加成。重要的是该反应适用于具有挑战性的单取代未活化烯烃，这在金催化中是前所未有的，并且在其他金属催化/促进的反应中几乎没有记录；此外，该反应表现出优异的区域选择性，比文献报道的要好得多。对于 1,2-二取代的未活化烯烃，该反应主要是立体有择的。