Preparation of 1,2,5-Trisubstituted 1<i>H</i>-Imidazoles from Ketenimines and Propargylic Amines by Silver-Catalyzed or Iodine-Promoted Electrophilic Cyclization Reaction of Alkynes
作者:Xiaorong Zhou、Zheng Jiang、Lexing Xue、Ping Lu、Yanguang Wang
DOI:10.1002/ejoc.201500704
日期:2015.9
From readily available propargylic amines, 1,2,5-trisubstituted imidazoles are efficiently obtained through a cascade reaction catalyzed by AgOTf or promoted by molecular iodine. The AgOTf-catalyzed reaction involves nucleophilic addition of propargylic amine to ketenimine, a silver-catalyzedelectrophiliccyclizationreaction of alkyne, and a tautomerism/isomerism/metal-H exchange cascade. The iodine-mediated
Palladium-Catalyzed Cyclocarbonylation of <i>o</i>-Iodoanilines with Heterocumulenes: Regioselective Preparation of 4(3<i>H</i>)-Quinazolinone Derivatives
作者:Chitchamai Larksarp、Howard Alper
DOI:10.1021/jo991922r
日期:2000.5.1
A catalyst system comprising palladium acetate-bidentate phosphine is effective for the cyclocarbonylation of o-iodoanilines with heterocumulenes at 70-100 degrees C for 12-24 h to give the corresponding 4(3H)-quinazolinone derivatives in good yields. Utilizing o-iodoaniline with isocyanates, carbodiimides, and ketenimines for the reaction, 2,4-( LH,3H)-quinazolinediones, 2-amino4(3H)-quinazolinones and 2-alkyl-4(3H)-quinazolinones were obtained, respectively. The nature of the substrates including the electrophilicity of the carbon center of the carbodiimide, and the stability of the ketenimine, influence the product yields of this reaction. Urea-type intermediates are believed to be generated first in situ from the reaction of o-iodoanilines with heterocumulenes, followed by palladium-catalyzed carbonylation and cyclization to yield the products.
Froyen,P., Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry, 1974, vol. 28, p. 586 - 588
作者:Froyen,P.
DOI:——
日期:——
L'abbe, Gerrit; Dekerk, Jean-Paul; Deketele, Martine, Bulletin des Societes Chimiques Belges, 1982, vol. 91, # 3, p. 243 - 248