Bioconjugation is the chemical strategy of covalent modification of biomolecules, using either an external reagent or other biomolecules. Since its inception in the twentieth century, the technique has grown by leaps and bounds, and has a variety of applications in chemical biology. However, it is yet to reach its full potential in the study of biochemical processes in live cells, mainly because the bioconjugation strategies conflict with cellular processes. This has mostly been overcome by using transition metal catalysts, but the presence of metal centers limit them to in vitro use, or to the cell surface. These hurdles can potentially be circumvented by using metal-free strategies. However, the very modifications that are necessary to make such metal-free reactions proceed effectively may impact their biocompatibility. This is because biological processes are easily perturbed and greatly depend on the prevailing inter- and intracellular environment. With this taken into consideration, this review analyzes the applicability of the transition-metal-free strategies reported in this decade to the study of biochemical processes in vivo.

中文翻译：

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使用无过渡金属技术实现细胞内生物偶联

生物共轭是使用外部试剂或其他生物分子对生物分子进行共价修饰的化学策略。自 20 世纪问世以来，该技术得到了突飞猛进的发展，并在化学生物学中得到了广泛的应用。然而，它在活细胞生化过程的研究中尚未发挥其全部潜力，主要是因为生物结合策略与细胞过程相冲突。这主要是通过使用过渡金属催化剂来克服的，但金属中心的存在将它们限制在体外使用，或到细胞表面。这些障碍可能可以通过使用无金属策略来规避。然而，使这种无金属反应有效进行所必需的修改可能会影响它们的生物相容性。这是因为生物过程很容易受到干扰，并且在很大程度上取决于普遍存在的细胞间和细胞内环境。考虑到这一点，本综述分析了近十年来报道的无过渡金属策略在体内生化过程研究中的适用性。