A new Cu-catalyzed efficient protocol is described for the transformation of oximes to the corresponding carbonate derivatives. Diisopropyl azodicarboxylate acted as a selective new precursor for the synthesis of oxime carbonates in high yields. The O–H bond cleavage and O–C bond formation occur in the presence of a copper catalyst providing a synthetically useful process, which tolerates a wide range
Metal-Free Selective Synthesis of 1,4-Dihydropyridazines from Hydroxypyrrolines and Hydrazines
作者:Dmitrii A. Shabalin、Marina Yu. Dvorko、Evgeniya E. Zolotareva、Igor' A. Ushakov、Alexander V. Vashchenko、Elena Yu. Schmidt、Boris A. Trofimov
DOI:10.1002/ejoc.201700589
日期:2017.7.25
An efficient and selective synthesis of 1,4-dihydropyridazines through the acid-catalyzed recyclization of 5-hydroxy-Δ1-pyrrolines with hydrazines has been developed. The scope of this reaction was thoroughly explored, resulting in the generation of a library of 1,4-dihydropyridazines in good to excellent yields (25 examples, 67–100 % yields).
Synthesis of 5-hydroxy-Δ1-pyrrolines from aryl isoalkyl ketoximes and acetylene in a tuned superbase medium
作者:Dmitrii A. Shabalin、Marina Yu. Dvorko、Elena Yu. Schmidt、Nadezhda I. Protsuk、Boris A. Trofimov
DOI:10.1016/j.tetlet.2016.06.025
日期:2016.7
The reactionbetweenaryl isoalkyl ketoximes and acetylene under atmospheric pressure was applied to the synthesis of 5-hydroxy-Δ1-pyrrolines, containing aromatic substituents at the carbon–nitrogen double bond, in moderate yields. A crucial factor for the synthesis is the accurate tuning of the system basicity to prevent further dehydration of the target compounds to 3H-pyrroles.
Synthesis of 5-hydroxy-Δ1-pyrrolines from sec-alkyl aryl ketoximes and acetylene
作者:Dmitrii A. Shabalin、Marina Yu. Dvorko、Elena Yu. Schmidt、Igor’ A. Ushakov、Boris A. Trofimov
DOI:10.1016/j.tet.2016.08.088
日期:2016.10
Synthesis of 5-hydroxy-Δ1-pyrrolines conjugated with aryl substituents has been effected via the rearrangement of O-vinylketoximes, having only one C–H bond adjacent to the oxime function and readily prepared by addition of sec-alkyl aryl ketoximes to acetylene. The target compounds were obtained in 80–86% yields (based on the O-vinylketoximes).
Site- and stereoselective synthesis of bridgehead tetrahydropyrrolo[2,3-c]pyridines from ketoximes and acetylene gas in two synthetic operations
作者:Dmitrii A. Shabalin、Igor' A. Ushakov、Anton V. Kuzmin、Alexander V. Vashchenko、Elena Yu. Schmidt、Boris A. Trofimov
DOI:10.1016/j.tetlet.2019.151533
日期:2020.2
3H-Pyrroles, synthesized in one-pot from ketoximes and acetylene gas in a KOH/DMSO system, undergo [4+2] cyclodimerization in the presence of t-BuOH (closed vessel, autogenic pressure, 140 °C, 8 h) to site- and stereoselectively afford partially hydrogenated bridgehead pyrrolo[2,3-c]pyridines in 15-60% yield. An essential feature of this synthesis is the activating effect of t-BuOH which is attributed