AbstractThe development of reagents that can selectively react in complex biological media is an important challenge. Here we show that N1‐alkylation of 1,2,4‐triazines yields the corresponding triazinium salts, which are three orders of magnitude more reactive in reactions with strained alkynes than the parent 1,2,4‐triazines. This powerful bioorthogonal ligation enables efficient modification of peptides and proteins. The positively charged N1‐alkyl triazinium salts exhibit favorable cell permeability, which makes them superior for intracellular fluorescent labeling applications when compared to analogous 1,2,4,5‐tetrazines. Due to their high reactivity, stability, synthetic accessibility and improved water solubility, the new ionic heterodienes represent a valuable addition to the repertoire of existing modern bioorthogonal reagents.
摘要开发能在复杂生物介质中选择性反应的试剂是一项重要挑战。在这里,我们展示了 1,2,4-三嗪的 N1-烷基化反应生成相应的三嗪盐,与母体 1,2,4-三嗪相比,这些三嗪盐在与应变炔反应中的反应活性高出三个数量级。这种功能强大的生物正交连接可有效地修饰肽和蛋白质。带正电荷的 N1-烷基三嗪盐具有良好的细胞渗透性,因此与类似的 1,2,4,5-四嗪相比,它们更适合细胞内荧光标记应用。由于这些新型离子杂二烯具有高反应性、稳定性、可合成性和更好的水溶性,是对现有现代生物正交试剂的重要补充。