An intermolecular annulation reaction of 2‐aryl‐1,3‐indandions with alkynes was reported using Pd(OAc)2 to access spirobi[indene]‐1,3‐diones. Under palladium catalysis, the substrates form a homocoupling dimer intermediate through a catalytic dehydrogenative cross‐coupling process. The palladium(II) species could come from dimer or 2‐aryl‐1,3‐indandion. Notably, this pathway is not typically observed in enol‐directed formal sp3 C‐H functionalization/oxidative annulation palladium chemistry. This transformation provides a route to access a class of functionalized spiro carbocyclic indenes.

中文翻译：

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Pd(II)催化C-H活化和炔烃成环反应合成1,2'-螺二[茚]-1,3-二酮


据报道，使用 Pd(OAc)2 进行 2-芳基-1,3-茚满二酮与炔烃的分子间成环反应，得到螺二[茚]-1,3-二酮。在钯催化下，底物通过催化脱氢交叉偶联过程形成同偶联二聚体中间体。钯 (II) 物质可能来自二聚体或 2-芳基-1,3-茚满二酮。值得注意的是，这种途径通常在烯醇导向的形式 sp3 C-H 官能化/氧化成环钯化学中观察不到。这种转化提供了获得一类官能化螺环碳环茚的途径。