郑州大学陈学年/马艳娜/马艳娜Nat. Catal.:钯催化α,β-不饱和羧酸和碳硼烷的不对称反式-Michael类加成反应
图1. TOC (图片来源于Nat. Catal.)The catalytic asymmetric Michael addition of α,β-unsaturated carbonyl compounds is one of the most valuable methods for constructing the β-carbon chirality centre because of its atom economy and efficiency. However, the catalytic asymmetric reverse α-addition of a nucleophile to an α,β-unsaturated carbonyl compound is much less common. Here we realize a palladium-catalysed asymmetric α-carboranylation of α,β-unsaturated carboxylic acids via an inverse electron-demand nucleophilic addition. The reaction features good B(9)-site selectivity of o/m-carboranes, precise α-regioselectivity towards α,β-unsaturated carboxylic acids, wide functional group tolerance and excellent enantioselectivities. A detailed reaction mechanism is proposed based on experimental and computational results that elucidates the origin of the enantioselectivity and α-selectivity. This finding has a guiding significance for the catalytic asymmetric anti-Michael-type addition of α,β-unsaturated carbonyl compounds and provides a different avenue for synthesizing α-chiral carboxylic acids.图2. 研究背景及本策略 (图片来源于Nat. Catal.)图3. 配体筛选 (图片来源于Nat. Catal.)图4. α,β-不饱和羧酸底物范围 (图片来源于Nat. Catal.)
图5. 碳硼烷底物范围 (图片来源于Nat. Catal.)
图6. 合成应用 (图片来源于Nat. Catal.)
图7. 机理研究 (图片来源于Nat. Catal.)
图8. DFT计算 (图片来源于Nat. Catal.)
图9. 可能的反应机理 (图片来源于Nat. Catal.)
In summary, a Pd(II)-catalysed asymmetric anti-Michael-type addition reaction of α,β-unsaturated carboxylic acids with carboranes using CPA as a ligand has been established. A series of α,β-unsaturated carboxylic acids ranging from cinnamic acid and corresponding derivatives to alkyl-substituted acrylic acids are effective substrates in this protocol, leading to the formation of α-carboranyl carboxylic acids in high yields and enantioselectivities. The experimental and computational studies have elucidated the reaction mechanism and origin of the enantiose lectivity. This highly selective anti-Michael-type addition reaction provides a general and straightforward method to introduce o-, m- and p-carboranes to the α-carbon-stereocentre of carboxylic acids under mild reaction conditions. Our ongoing efforts in the laboratory involve more detailed mechanistic investigations and the expansion of the nucleophile and alkene scope.Lei, C., Lu, W., Shen, T. et al. Palladium-catalysed asymmetric anti-Michael-type addition of α,β-unsaturated carboxylic acids with carboranes. Nat Catal (2026). https://doi.org/10.1038/s41929-026-01480-4
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