Pd‐Catalyzed versus Uncatalyzed, PhI(OAc)
<sub>2</sub>
‐Mediated Cyclization Reactions of
<i>N</i>
<sup>6</sup>
‐([1,1′‐Biaryl]‐2‐yl)Adenine Nucleosides
作者:Sakilam Satishkumar、Suresh Poudapally、Prasanna K. Vuram、Venkateshwarlu Gurram、Narender Pottabathini、Dellamol Sebastian、Lijia Yang、Padmanava Pradhan、Mahesh K. Lakshman
DOI:10.1002/cctc.201700918
日期:2017.11.9
3,3‐hexafluoroisopropanol (HFIP). Thus, under Pd catalysis and in HFIP, reactions proceed to provide carbazolyl nucleoside analogues, with some differences. If reactions of N6‐biarylyl nucleoside substrates were conducted in MeCN, formation of aryl benzimidazopurinyl nucleoside derivatives was observed in many cases by C−N bond formation with the N1 ring nitrogen atom of the purine (carbazole and benzimidazole
在这项工作中,我们通过Pd II / Pd IV氧化还原循环评估了N 6 -([1,1'-联芳基] -2-基)腺嘌呤核苷与Pd(OAc)2和PhI(OAc)2的反应。底物很容易通过Pd / Xantphos催化的腺嘌呤核苷与2-bromo-1,1'-biaryls的反应而获得。在PhMe中,N 6-联芳基核苷通过与环外N 6的C-N键形成而得到C6-咔唑基核苷类似物氮原子。在Pd催化反应的溶剂筛选中,发现未催化的过程是可行的。据观察,咔唑基产物也可以在不存在金属催化剂的情况下,通过与PhI(OAc)2在1,1,1,3,3,3-六氟异丙醇(HFIP)中反应而获得。因此,在Pd催化下和在HFIP中,反应进行提供了咔唑基核苷类似物,但有一些区别。如果在MeCN中进行N 6-联芳基核苷底物的反应,则在许多情况下通过与嘌呤的N 1环氮原子形成CN键可观察到芳基苯并咪唑嘌呤基核苷衍生物的形成(咔唑和苯并咪唑异构体很容易通过色谱)。而Pd