Herein, we report that under mild solvolytic conditions, enantioenriched bromochlorides can be ionized, stereospecifically cyclized to an array of complex bromocyclic scaffolds, or intermolecularly trapped by exogenous nucleophiles. Mechanistic investigations support an ionic mechanism wherein the bromochloride serves as an enantioenriched bromonium surrogate. Several natural product-relevant motifs are accessed in enantioenriched form for the first time with high levels of stereocontrol, and this technology is applied to the scalable synthesis of a polycyclic brominated natural product. Arrays of nucleophiles including olefins, alkynes, heterocycles, and epoxides are competent traps in the bromonium-induced cyclizations, leading to the formation of enantioenriched mono-, bi-, and tricyclic products. This strategy is further amenable to intermolecular coupling between cinnamyl bromochlorides and a diverse set of commercially available nucleophiles. Collectively, this work demonstrates that enantioenriched bromonium chlorides are configurationally stable under solvolytic conditions in the presence of a variety of functional groups.

中文翻译：

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溴氯化物的对映体溶剂化功能化

在本文中，我们报道了在温和的溶剂分解条件下，对映体富集的溴氯化物可以被电离，立体定向环化成一系列复杂的溴环骨架，或被外源性亲核试剂分子间捕获。机理研究支持离子机制，其中溴氯化物用作对映体富集的溴替代物。首次以高对映体控制形式以对映体富集的形式获得了几种与天然产物相关的基序，并将该技术应用于多环溴化天然产物的可扩展合成。包括烯烃，炔烃，杂环和环氧化物在内的亲核试剂阵列是溴诱导的环化反应中的有效陷阱，导致形成对映体富集的单环，双环和三环产物。该策略还适于肉桂酰溴氯化物与多种可商购的亲核试剂之间的分子间偶联。总的来说，这项工作表明，在各种官能团存在的情况下，溶剂化条件下富含对映体的氯化溴在构型上是稳定的。