河南农业大学杨西发/陕西师范大学李兴伟ACS Catal.:利用C-H活化和环状二芳基碘盐的阻转异构选择性开环不对称合成轴手性联芳化合物
图1. TOC (图片来源于ACS Catal.)Asymmetric ring-opening of cyclic diaryliodonium salts has emerged as an efficient strategy for accessing axially chiral biaryls. However, existing methods are largely restricted to copper catalyzed reactions using heteroatom nucleophiles, and general enantioselective C−C bond-forming approaches remain elusive. Herein, we disclose a Rh(III)-catalyzed enantioselective arylation and acylation of cyclic diaryliodonium salts by the merger of C−H activation and atroposelective ring opening of cyclic diaryliodonium salts. This transformation enables asymmetric conversion of cyclic diaryliodonium salts with electron-poor arenes and aldehydes as coupling partners. The protocol affords two structurally distinct classes of axially chiral biaryls with broad substrate scope (92 exam ples), generally good yields, and enantioselectivities (up to >99% ee). Derivatization applications highlight the synthetic applicability and potential of the axially chiral scaffolds. This work provides a platform for the modular synthesis of multifunctional, highly enantioenriched axially chiral biaryl frameworks and expands the reaction paradigm of asymmetric transformations of cyclic diarylio donium salts.图2. 研究背景及本策略 (图片来源于ACS Catal.)图3. 条件优化 (图片来源于ACS Catal.)图4. 苯甲酰胺和环状二芳基碘盐底物范围 (图片来源于ACS Catal.)图5. N-磺酰基-2-氨基苯甲醛和环状二芳基碘盐底物范围 (图片来源于ACS Catal.)图6. 合成应用 (图片来源于ACS Catal.)图7. 机理研究 (图片来源于ACS Catal.)In summary, we have achieved the first enantioselective arylation and acylation of cyclic diaryliodonium salts through integration of RhIII-catalyzed C−H activation and hypervalent iodine chemistry. This catalytic system is applicable to electron-poor arenes and aldehydes (C(acyl)−H bond) by leveraging desymmetrization transformation of the iodonium salts, overcoming a long-standing challenge in metal-catalyzed asymmetric functionalization of cyclic diaryl iodoniums. The methodology provides direct access to two structurally distinct classes of chiral biaryls with exceptional enantioselectivity (up to >99% ee) and broad functional group tolerance (92 substrates). The synthetic utility of the products is further highlighted in successful derivatization reactions. Preliminary mechanistic studies suggest that the C(acyl)−H activation step is involved in the rate-limiting step. Given the wide availability and abundance of arenes and aldehydes, this strategy holds significant potential for broad applications, thereby enabling new avenues for constructing novel axially chiral biaryls with cyclic diaryliodonium salts.DOI: https://doi.org/10.1021/acscatal.6c05589声明：本文中广告内容由广告主提供，请您在购买任何商品或服务前，以书面合同形式明确约定双方权利义务，本账号不对其后续经营行为承担持续担保责任
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