Silver(I)‐ and Base‐Mediated formal [4+3] Cycloaddition of
<i>in Situ</i>
generated 1,2‐Diaza‐1,3‐dienes with
<i>C,N</i>
‐Cyclic Azomethine Imines: An Efficient Protocol for the Synthesis of Tetrazepine Derivatives
作者:Zefei Li、Shuaikang Li、Tianjiao Kan、Xinyue Wang、Xin Xin、Yunlei Hou、Ping Gong
DOI:10.1002/adsc.202000398
日期:2020.7.16
A silver(I)‐ and base‐mediated formal [4+3] cycloadditionreaction of in situ generated 1,2‐diaza‐1,3‐dienes with in situ formed C,N‐cyclic azomethine imines has been developed. This protocol provided an efficient method for the synthesis of biologically important 1,2,4,5‐tetrazepine derivatives with a wild substrate scope and excellent functional group tolerance in moderate to excellent yields.
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。
Synthesis of Isoquinolinium-2-yl Amides via Silver(I)-Catalyzed Ring Closure of N′-(2-Alkynylbenzylidene)hydrazides
作者:Denis Ermolat’ev、Erik Van der Eycken、Vsevolod Peshkov、Olga Pereshivko、Sofie Van Hove
DOI:10.1055/s-0030-1260219
日期:2011.10
An efficient one-pot protocol for the synthesis of isoquinolinium-2-yl amides starting from readily available hydrazides and 2-alkynylbenzaldehydes is described. The key step of the protocol is a silver(I)-catalyzed ring-closure of N′-(2-alkynylbenzylidene)hydrazides that are generated in situ. Isoquinolinium-2-yl amides derived from tert-butoxycarbonyl hydrazide could be further deprotected, delivering
Synthesis of H-Pyrazolo[5,1-a]isoquinolines via Silver(I)-Catalyzed Tandem Reaction of N′-(2-Alkynylbenzylidene)hydrazides with Propargyl Amine Derivatives
作者:Zhiyong Wang、Gang Liu、Hongliang Liu、Shouzhi Pu
DOI:10.1055/s-0033-1340486
日期:——
Abstract We have developed a tandemreaction of N′-(2-alkynylbenzylidene)hydrazides with propargyl amine derivatives catalyzed by silver triflate to provide 2-(aminomethyl)-H-pyrazolo[5,1-a]isoquinolines. This reaction proceeds through a tandem 6-endo-cyclization, nucleophilic addition, 5-endo-cyclization and aromatization, leading to the cycloadducts in moderate to good yields with exclusive regioselectivity
摘要 我们已经开发的一个串联反应Ñ ' - (2- alkynylbenzylidene)与三氟甲磺酸银催化以提供炔丙基胺衍生物酰肼2-(氨基甲基) - H ^ -吡唑并[5,1-一个]异喹啉。这通过一个串联反应进行6-内切-cyclization,亲核加成,5-内切-cyclization和芳构化,导致在cycloadducts中度至良好的产率与独占的区域选择性。 我们已经开发的一个串联反应Ñ ' - (2- alkynylbenzylidene)与三氟甲磺酸银催化以提供炔丙基胺衍生物酰肼2-(氨基甲基) - H ^ -吡唑并[5,1-一个]异喹啉。这通过一个串联反应进行6-内切-cyclization,亲核加成,5-内切-cyclization和芳构化,导致在cycloadducts中度至良好的产率与独占的区域选择性。