Synthesis of Pyrrolotriazoloisoquinoline Frameworks by Intramolecular Cu-Mediated or Free Radical Arylation of Triazoles
作者:Liya D. Funt、Olesya A. Tomashenko、Ivan P. Mosiagin、Mikhail S. Novikov、Alexander F. Khlebnikov
DOI:10.1021/acs.joc.7b01341
日期:2017.7.21
insight into the mechanism of the triazole ring cleavage was achieved by performing a DFT study at the B3LYP/6-31G+(d,p) level. Free radical cyclization of (2-bromophenyl)pyrrolyl-1,2,4-triazoles with TTMSS/AIBN under neutral conditions allows obtaining pyrrolo[3,2-c][1,2,4]triazolo[5,1-a] and [3,4-a]isoquinolines, as well two more new heterocyclic systems, pyrrolo[3,4-c][1,2,4]triazolo[5,1-a] and [3,4-a]isoquinolines
经由铜介导的1,2,4-三唑的分子内直接C-芳基化反应,首先在三唑-NHC控制下完成(2-溴苯基)吡咯基-1,2,4-三唑的环化反应,得到未知的稠合杂环骨架,吡咯并[3,2- c ] [1,2,4]三唑并[5,1- a ]或[3,4- a ]异喹啉。初级产物在碱性芳基化条件下经历三唑开环,提供N-(1 H-吡咯并[3,2 - c ]异喹啉-5-基)氰酰胺。由异构吡咯并[3,2- c ] [1,2,4]三唑并[3,4- a异喹啉除三唑开环外还涉及氰基的异常迁移。氰胺可轻松还原为1 H-吡咯并[3,2- c ]异喹啉的第一个NH 2取代衍生物1 H-吡咯并[3,2- c ]异喹啉-5-胺。通过在B3LYP / 6-31G +(d,p)水平上进行DFT研究,可以深入了解三唑环裂解的机理。在中性条件下用TTMSS / AIBN将(2-溴苯基)吡咯基-1,2,4-三唑进行自由基环化可得到吡咯并[3,2-