Teaching bismuth to make and break bonds One major reason why transition metals are good catalysts is that they can shuttle between oxidation states. This flexibility lets them slide in and out of chemical bonds; so, for instance, they can snip a bond between carbon and boron and then stitch a carbonfluorine bond in its place. Planas et al. now report that bismuth can also orchestrate such bond-swapping events. They implement a fully catalytic cycle for fluorination of aryl boronates, in which bismuth hops between its +3 and +5 oxidation states. Science, this issue p. 313 Bismuth can cycle through oxidation states to stitch together carbon-fluorine bonds in a manner akin to that of transition metals. Bismuth catalysis has traditionally relied on the Lewis acidic properties of the element in a fixed oxidation state. In this paper, we report a series of bismuth complexes that can undergo oxidative addition, reductive elimination, and transmetallation in a manner akin to transition metals. Rational ligand optimization featuring a sulfoximine moiety produced an active catalyst for the fluorination of aryl boronic esters through a bismuth (III)/bismuth (V) redox cycle. Crystallographic characterization of the different bismuth species involved, together with a mechanistic investigation of the carbon-fluorine bond-forming event, identified the crucial features that were combined to implement the full catalytic cycle.

中文翻译：

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铋氧化还原催化芳基硼酸酯氟化

教铋建立和断开键 过渡金属是良好催化剂的一个主要原因是它们可以在氧化态之间穿梭。这种灵活性使它们能够滑入和滑出化学键；因此，例如，他们可以剪断碳和硼之间的键，然后在其位置缝合碳氟键。普拉纳斯等人。现在报告说，铋也可以编排这种键交换事件。他们实现了芳基硼酸酯氟化的完全催化循环，其中铋在其 +3 和 +5 氧化态之间跳跃。科学，这个问题 p。313 铋可以通过氧化态循环，以类似于过渡金属的方式将碳-氟键缝合在一起。铋催化传统上依赖于固定氧化态元素的路易斯酸性。在本文中，我们报告了一系列铋配合物，它们可以以类似于过渡金属的方式进行氧化加成、还原消除和金属转移。以亚砜亚胺部分为特征的合理配体优化为芳基硼酸酯通过铋 (III)/铋 (V) 氧化还原循环氟化产生了活性催化剂。所涉及的不同铋物种的晶体学表征，以及对碳氟键形成事件的机械研究，确定了结合实施完整催化循环的关键特征。以亚砜亚胺部分为特征的合理配体优化产生了一种活性催化剂，用于通过铋 (III)/铋 (V) 氧化还原循环氟化芳基硼酸酯。所涉及的不同铋物种的晶体学表征，以及对碳氟键形成事件的机械研究，确定了结合实施完整催化循环的关键特征。以亚砜亚胺部分为特征的合理配体优化产生了一种活性催化剂，用于通过铋 (III)/铋 (V) 氧化还原循环氟化芳基硼酸酯。所涉及的不同铋物种的晶体学表征，以及对碳氟键形成事件的机械研究，确定了结合实施完整催化循环的关键特征。