A Cascade Approach to Pyridines from 2-Azido-2,4-dienoates and α-Diazocarbonyl Compounds
摘要:
A one-pot synthesis of substituted pyridines via a cascade reaction of 2-azido-24-dienoates with alpha-diazocarbonyl compounds and triphenylphosphine is reported. The process involves a Staudinger-Meyer reaction, a Wolff rearrangement, ail aza-Wittig reaction, and an electrocyclic ring- closure. The procedure is general and efficient. The substrates are readily available.
The migration ability of hydrogen, the methyl, phenyl, p-methoxyphenyl, and p-nitrophenyl groups in the Wolff-rearrangement has been investigated with the aroyl-acyl-diazomethanes 1a-d. The results of the thermal and photochemical (direct and sensitized) reaction are discussed. The insertion of the intermediate aroyl-acylcarbenes 2 in the OH-bond of ethanol yielding 2-ethoxy-1,3-diketones 7 competes
Tandem Synthesis of Benzo[<i>b</i>]carbazoles and Their Photoluminescent Properties
作者:Yanpeng Xing、Binbin Hu、Qijun Yao、Ping Lu、Yanguang Wang
DOI:10.1002/chem.201301887
日期:2013.9.16
5 H‐Benzo[b]carbazoles were prepared through a tandem reaction between 2‐ethynyl‐N‐triphenylphosphoranylidene anilines and α‐diazoketones through ketenimine intermediates in moderate‐to‐good yields. By using this approach, benzo[b]benzo[5,6]indolo[3,2‐h]carbazoles, fluoreno[9,1‐ab]carbazoles, and fluoreno[9,1‐ab]fluoreno[1′,9′:5,6,7]indolo[3,2‐h]carbazoles were constructed in one pot. Moreover, the
通过2-乙炔基-N-三苯基磷酰亚苯胺苯胺和α-二氮酮通过酮亚胺中间体的串联反应,以中等至良好的产率制备了5 H-苯并[ b ]咔唑。通过使用这种方法,苯并[ b ]苯并[5,6]吲哚并[3,2- h ]咔唑,芴[9,1- ab ]咔唑和芴[9,1- ab ]氟[1',9 ′:5,6,7] indolo [3,2- h ]咔唑是在一个锅中制成的。而且,最终产物发出的光在410-521 nm范围内,量子产率高达62%。
A Tandem Approach to Isoquinolines from 2-Azido-3-arylacrylates and α-Diazocarbonyl Compounds
作者:Yun-Yun Yang、Wang-Ge Shou、Zheng-Bo Chen、Deng Hong、Yan-Guang Wang
DOI:10.1021/jo8003259
日期:2008.5.1
2-Azido-3-arylacrylates react with α-diazocarbonyl compounds and triphenylphosphine to furnish isoquinolines in 60−92% yields. The tandem process involves a Wolff rearrangement, an aza-Wittig reaction, and an electrocyclic ringclosure. The procedure is efficient, rapid, and general, and the substrates are readily available.
The Rhodium(II) Acetate-Catalyzed Reaction of Diacyldiazomethanes with Isothiocyanates: Formation of 2-Thioxo-2H-1,3-oxazin-4(3H)-one.
作者:Hirofumi Nakano、Toshikazu Ibata
DOI:10.1246/bcsj.66.238
日期:——
The rhodium(II) acetate-catalyzed reaction of diacyldiazomethanes such as dibenzoyldiazomethane, acetylaroyldiazomethanes, diacetyldiazomethane, and diazodimedone with isothiocyanates gave 2-thioxo-2H-1,3-oxazin-4(3H)-ones through the [4+2] cycloaddition of isothiocyanates with acylketenes which were derived by the Wolff rearrangement of the diacyldiazomethanes. Migration aptitude of methyl and aryl groups was discussed in the reaction of acetylaroyldiazomethanes.