作者:Lakshman, Mahesh K.、Malinchak, Casina T.、Shank, Nathaniel、Neary, Michelle C.、Stahl, Lothar
DOI:10.1039/d4ob00689e
日期:——
nitrogen atoms can lead to relatively facile remote functionalization, yielding modified purinyl motifs that are otherwise not easily obtained. Herein, we report previously undescribed N-directed aroylation of 6-arylpurine ribo and the more labile 2′-deoxyribonucleosides. Kinetic isotope analysis as well as reaction with a well-defined dimeric, palladated 9-benzyl 6-arylpurine provided evidence for
嘌呤环含有四个不同碱度的嵌入氮原子。选择性利用这些环氮原子可以导致相对容易的远程功能化,产生不易获得的修饰的嘌呤基基序。在此,我们报道了先前未描述的 6-芳基嘌呤核糖和更不稳定的 2'-脱氧核糖核苷的N定向芳酰化。动力学同位素分析以及与明确的二聚体、钯化 9-苄基 6-芳基嘌呤的反应为N定向环金属化作为关键步骤提供了证据,并具有合理的限速 C-H 键断裂。自由基抑制实验表明芳酰基自由基可能具有中间作用。该化学克服了多氮和多氧核苷结构的功能化中经常遇到的困难,这些核苷结构具有复杂的反应性和对 2'-脱氧底物更敏感的不稳定糖苷键。