4-(1-Aminoallylidene)isoxazol-5-ones were synthesized in good yields by the [2 + 2]cycloaddition-retro-electrocyclization reaction of 4-methylideneisoxazol-5(4)-ones with ynamines. The reaction mechanism and the absence of hetero-Diels-Alder cycloadducts were investigated by DFT calculations. 4-(1-Aminoallylidene)isoxazol-5-ones were found to be convenient substrates for the preparation of 4-aminopyridines under thermal metal-free conditions. The process proceeds via decarboxylative isomerization with cyclic amino groups and accompanied by partial dealkylation of acyclic amino groups. 4-Aminopyridines can also be prepared directly from 4-methylideneisoxazol-5(4)-ones and ynamines by the one-pot protocol.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.joc.3c00654 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Reactivity Profiling for High-Yielding Ynamine-Tagged Oligonucleotide Click Chemistry Bioconjugations.
Bioconjug Chem
November 2024
Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K.
Article Synopsis
- The CuAAC reaction is essential for creating bioconjugates but can cause oxidative damage due to the use of copper catalysts.
- Ynamines are shown to be more effective in these reactions, allowing for lower copper usage and faster formation of 1,4-triazole products.
- This study identifies optimal conditions for synthesizing oligodeoxyribonucleotide bioconjugates, demonstrating that ynamine-based reactions outperform traditional CuAAC methods and enhancing the efficiency of bioconjugate preparation.
Rhodium-Catalyzed Regioselective [4 + 2] Cycloaddition of Ynamines and 2-(Cyanomethyl)phenylboronates.
Org Lett
August 2024
College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325035, China.
A rhodium-catalyzed [4 + 2] cycloaddition of ynamines and 2-(cyanomethyl)phenylboronates has been developed, leading to efficient and excellent regioselective synthesis of valuable indole-linked aromatic compounds in a concise and flexible approach. Interestingly, this strategy was successful in the construction of C···N axially chiral indoles with high enantiocontrol by the introduction of a new phosphoramidite ligand (Xie-Phos).
View Article and Find Full Text PDFChemodivergent Synthesis of Polycyclic Aromatic Diarylamines and Carbazoles by Thermal/Photochemical Process-Controlled Dephosphinylative Functionalizations of Amino(phosphinyl)arenes.
J Org Chem
June 2024
Department of Applied Chemistry, Faculty of Engineering, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005, Japan.
A chemodivergent synthesis of polycyclic aromatic diarylamines and carbazoles was established by employing thermally or photochemically controlled processes using KOBu/1,10-phenanthroline. The synthetic processes involved the dephosphinylation of 9-amino-10-(phosphinyl)phenanthrenes, which were obtained through a regioselective palladium-catalyzed direct [4 + 2] benzannulation of phosphinyl ynamines with 2-iodobiphenyls. When the dephosphinylation was conducted under heating conditions (∼100 °C), it proceeded to yield 9-aminophenanthrene.
View Article and Find Full Text PDFMechanistic Basis of the Cu(OAc) Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction.
J Am Chem Soc
May 2024
Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K.
The Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction is used as a ligation tool throughout chemical and biological sciences. Despite the pervasiveness of CuAAC, there is a need to develop more efficient methods to form 1,4-triazole ligated products with low loadings of Cu. In this paper, we disclose a mechanistic model for the ynamine-azide (3 + 2) cycloadditions catalyzed by copper(II) acetate.
View Article and Find Full Text PDFGlutathione Mediates Control of Dual Differential Bio-orthogonal Labelling of Biomolecules.
Angew Chem Weinheim Bergstr Ger
December 2023
Traditional approaches to bio-orthogonal reaction discovery have focused on developing reagent pairs that react with each other faster than they are metabolically degraded. Glutathione (GSH) is typically responsible for the deactivation of most bio-orthogonal reagents. Here we demonstrate that GSH promotes a Cu-catalysed (3+2) cycloaddition reaction between an ynamine and an azide.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!