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。
Ruthenium(II)-Porphyrin Catalyzed Selective N-Imidation of Aromatic Nitrogen Heterocycles
Ruthenium(II)-porphyrin (0.5 mol%) catalyzed N-imidations of aromatic nitrogen heterocycles with phenyl(tosylimino)iodinane under mild conditions were achieved in good yields (<94%). The effects of substituent, catalyst, temperature, and solvent on the reaction have been investigated. It was found that the catalyst significantly affected the yield and selectivity of imidation reaction for aromatic nitrogen heterocycles at 30 °C.
<i>N</i>-Heterocyclic Carbene Catalyzed Enantioselective [3 + 2] Dearomatizing Annulation of Saturated Carboxylic Esters with <i>N</i>-Iminoisoquinolinium Ylides
作者:Pengfei Zhang、Yu Zhou、Xu Han、Jinyi Xu、Hong Liu
DOI:10.1021/acs.joc.8b00227
日期:2018.4.6
dearomatizing annulationreaction is a significant challenge in organic chemistry. The direct activation of α-carbons of simple saturated esters, as nucleophiles, is an important synthesis strategy. In the present study, we disclose [3 + 2] dearomatizing annulationreactions with direct activating α-carbons of saturated carboxylic esters and N-iminoisoquinolinium ylides, which possess highly enantioselective
The reaction of N-tosyliminoisoquinolinium ylides with trimethylsilylketene as a C2 unit introducing reagent, giving unexpected [3+2] cycloadducts, pyrazolo[5,1-a]isoquinolines, is described.
描述了N-甲苯磺酰基异喹啉鎓基化物与三甲基甲硅烷基乙烯酮作为C 2单元引入试剂的反应,产生了意外的[3 + 2]环加合物,吡唑并[5,1- a ]异喹啉。
A New Rhodium/Copper-Cocatalyzed C–H Oxidation for the Preparation of Isoquinolin-1-ones
作者:Yi-Lin Liu、Chen-Liang Deng、Zeng-Le Zhou、Jian-Lan Song
DOI:10.1055/s-0035-1561947
日期:——
Abstract A new and efficient rhodium/copper-cocatalyzed C–H oxidation reaction of isoquinolinium N-amides has been developed. In the presence of rhodium(II) acetate dimer, copper(II) chloride, a ligand and sodium tert-butoxide, a variety of isoquinolin-1-ones were prepared in moderate to good yields via ortho C–H oxidation. A new and efficient rhodium/copper-cocatalyzed C–H oxidation reaction of isoquinolinium