Aryne [3 + 2] cycloaddition with N-sulfonylpyridinium imides and in situ generated N-sulfonylisoquinolinium imides: a potential route to pyrido[1,2-b]indazoles and indazolo[3,2-a]isoquinolines
作者:Jingjing Zhao、Pan Li、Chunrui Wu、Hongli Chen、Wenying Ai、Renhong Sun、Hailong Ren、Richard C. Larock、Feng Shi
DOI:10.1039/c2ob06611d
日期:——
The aryne [3 + 2] cycloaddition process with pyridinium imides breaks the aromaticity of the pyridine ring. By equipping the imide nitrogen with a sulfonyl group, the intermediate readily eliminates a sulfinate anion to restore the aromaticity, leading to the formation of pyrido[1,2-b]indazoles. The scope and limitation of this reaction are discussed. As an extension of this chemistry, N-tosylisoquinolinium
与吡啶鎓酰亚胺的芳烃[3 + 2]环加成过程破坏了吡啶环的芳香性。通过在酰亚胺氮上加成磺酰基,该中间体容易消除亚磺酸根阴离子以恢复芳香性,从而导致吡啶并[1,2- b ]吲唑的形成。讨论了该反应的范围和局限性。作为该化学反应的扩展,通过AgOTf催化的6-endo-dig亲电环化反应从N '-(2-炔基亚苄基)-甲苯磺酰肼原位生成的N-甲苯磺酰异喹啉鎓亚胺易于进行芳烃[3 + 2]环加成反应而制得吲哚唑[3,2- a同一锅中的]-异喹啉,为这些潜在的抗癌药提供了高效途径。
endergonic formation of the intermediate complex of nitrobiarenes and PPh3, which corresponds with experimental findings regarding reactiontemperature. The robust synthetic capacity of the photoredox Cadogan reaction systems has been demonstrated by the viable productivity of a broad range of carbazoles and related N-heterocycles with good tolerance of various functionalities.
已发现可见光驱动的光化学卡多根型环化。发现有机 DA 型光敏剂 4CzIPN 是将能量从光子转移到瞬态中间体的有效介质,该中间体打破了卡多根反应中的脱氧壁垒,并使无温和金属的咔唑和相关杂环成为可能。DFT 计算结果表明硝基双芳烃和 PPh 3的中间体复合物的温和吸能形成,这与关于反应温度的实验结果一致。光氧化还原 Cadogan 反应系统的强大合成能力已通过广泛范围的咔唑和相关N-杂环的可行生产力得到证明,这些N-杂环对各种官能团具有良好的耐受性。
REACTIONS OF SUBSTITUTED PYRIDINIUM<i>N</i>-IMINES WITH BENZYNE: SYNTHESES OF PYRIDO[1,2-<i>b</i>]INDAZOLES AND RELATED COMPOUNDS
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.
Rh(III)-Catalyzed Synthesis of Indazolo[2,3-<i>a</i>]quinolines: Vinylene Carbonate as C1 and C2 Building Blocks
作者:Wei Hu、Chao Pi、Di Hu、Xiliang Han、Yangjie Wu、Xiuling Cui
DOI:10.1021/acs.orglett.2c00580
日期:2022.4.15
rhodium-catalyzed cyclization of azobenzenes and vinylene carbonate via C–H bond activation to construct indazolo[2,3-a]quinolines has been developed. This protocol offers an efficient method for synthesis of the titled products in good yields with broad functional group tolerance. In this reaction, three C–C bonds and C–N bond are formed in one pot, and vinylene carbonate (VC) acts as C1 and C2 synthons as well as
铑催化偶氮苯和碳酸亚乙烯酯通过C-H键活化环化制备吲唑并[2,3- a ]喹啉。该协议提供了一种有效的方法来合成具有广泛功能组耐受性的高产量的标题产品。在这个反应中,三个C-C键和C-N键在一锅中形成,并且碳酸亚乙烯酯(VC)作为C1和C2合成子以及“亚乙烯基转移”剂和酰化剂构建目标融合杂环。此外,这些产品表现出良好的荧光特性,表明它们具有作为荧光材料和生物传感器的潜在应用。
Oxidative C–H/C–H Annulation of Imidazopyridines and Indazoles through Rhodium-Catalyzed Vinylene Transfer
作者:Koushik Ghosh、Yuji Nishii、Masahiro Miura
DOI:10.1021/acs.orglett.0c00975
日期:2020.5.1
Transition-metal-catalyzed C-Hactivation followed by oxidative annulation with alkynes has been an efficient synthetic tool for the assembly of various polyaromatic scaffolds. Despite the substantial progress in this field, it is still a significant challenge to achieve the synthesis of nonsubstituted vinylene-fused compounds. In this contribution, we report a Rh-catalyzedC-H/C-H vinylene cyclization adopting