金催化的β-区域选择性正式[3 + 2]酰胺与吡咯并[1,2- b ]吲唑的环加成反应:反应发展和机理研究
摘要:
在这里,我们报道了前所未有的金(I)诱导的酰胺与吡啶并[1,2- b ]吲唑的金(I)诱导的β位区域选择性形式[3 + 2]环加成反应,得到3-酰胺基7-(吡啶-2'-基吲哚具有良好的优良收率。首次分离了金(I)催化剂与乙酰胺的配合物,并首次通过X射线衍射分析对其进行了表征。机理研究表明,该反应途径涉及金稳定的碳正离子中间体,该中间体依次参与了苯环邻位的连续C–H键功能化。
Reactions of benzyne with several pyridinium N-imines were examined. 2-o-Aminophenylpyridine derivatives 6, pyrido[1,2-b]indazoles (7), indazolo[2,3-a]quinoline (17), and indazolo[3,2-a]isoquinoline (18) were obtained by the reactions of benzyne with the corresponding ylides 5, 10, 15, and 16, respectively.
Synthesis of Pyrido[1,2-<i>b</i>]indazoles via Aryne [3 + 2] Cycloaddition with <i>N</i>-Tosylpyridinium Imides
作者:Jingjing Zhao、Chunrui Wu、Pan Li、Wenying Ai、Hongli Chen、Chaojie Wang、Richard C. Larock、Feng Shi
DOI:10.1021/jo200863e
日期:2011.8.19
The [3 + 2] cycloaddition of arynes with N-tosylpyridinium imides, followed by an elimination of Ts-, affords pyrido[1,2-b]indazoles under mild reaction conditions in good yields.
Pd-Catalyzed Tandem C–H Azidation and N–N Bond Formation of Arylpyridines: A Direct Approach to Pyrido[1,2-<i>b</i>]indazoles
A novel Pd-catalyzed nitrogenation of arylpyridines via C-H azidation has been developed. Direct C-N and N-N formations are achieved for this N-atom incorporation transformation using azides as the N-atom source. This method provides an alternatively concise approach for the construction of bioactively important pyrido[1,2-b]indazoles.