Bioorthogonal chemical reactions have emerged as convenient and rapid methods for incorporating unnatural functionality into living systems. Different prototype reactions have been optimized for use in biological settings. Optimization of 3 + 2 dipolar cycloadditions involving nitrones has resulted in highly efficient reaction conditions for bioorthogonal chemistry. Through substitution at the nitrone carbon or nitrogen atom, stereoelectronic tuning of the reactivity of the dipole has assisted in optimizing reactivity. Nitrones have been shown to react rapidly with cyclooctynes with bimolecular rate constants approaching k₂ = 10² M^–1 s^–1, which are among the fastest bioorthogonal reactions reported (McKay et al. Org. Biomol. Chem.2012, 10, 3066–3070). Nitrones have also been shown to react with trans-cyclooctenes (TCO) in strain-promoted TCO-nitrone cycloadditions reactions. Copper catalyzed reactions involving alkynes and nitrones have also been optimized for applications in biology. This review provides a comprehensive accounting of the different bioorthogonal reactions that have been developed using nitrones as versatile reactants, and provides some recent examples of applications for probing biological systems.

中文翻译：

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在环加成反应中利用硝酮作为多功能偶极子的生物正交反应

生物正交化学反应已成为将非自然功能整合到生命系统中的方便快捷的方法。不同的原型反应已被优化用于生物环境。涉及硝酮的 3 + 2 偶极环加成的优化为生物正交化学提供了高效的反应条件。通过取代硝酮碳或氮原子，偶极子反应性的立体电子调谐有助于优化反应性。硝酮已被证明与环辛炔快速反应，双分子速率常数接近k ₂ = 10 ² M ^–1 s ^–1，这是报道的最快的生物正交反应之一（McKay 等人，2007 年）。组织。生物分子。化学 2012 , 10 , 3066–3070)。硝酮也已显示在应变促进的 TCO-硝酮环加成反应中与反式环辛烯 (TCO) 反应。涉及炔烃和硝酮的铜催化反应也已针对生物学应用进行了优化。这篇综述全面介绍了使用硝酮作为通用反应物开发的不同生物正交反应，并提供了一些最新的生物系统探测应用实例。