Various 2-amino-3-cyanoindoles are synthesized through copper catalyzed intramolecular N-arylations of ketene aminals at room temperature for the first time with 60-99% yields within 0.1-2 h. Controlled regioselective N-arylations of unsymmetrical ketene aminals are also studied. Further, a new double heteroannulation approach is demonstrated for the synthesis of 11-aminoindolo[2,3- b]quinolines from acyclic and nonheterocyclic precursors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.joc.8b00816 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bench-Stable 2-Halopyridinium Ketene Hemiaminals as Reagents for the Synthesis of 2-Aminopyridine Derivatives.
Org Lett
November 2024
Chemistry Department, Hamilton College, 198 College Hill Rd., Clinton, New York 13323, United States.
2-Chloro-1-(1-ethoxyvinyl)pyridinium triflate and several other bench-stable -(1-alkoxyvinyl) 2-halopyridinium triflates have been developed as reagents for the synthesis of valuable 2-aminopyridine scaffolds via unusually mild SAr substitutions with amine nucleophiles. Advantages of this approach include an operationally simple mix-and-stir procedure at room temperature or mild heat and ambient atmosphere and without the need for transition metal catalysts, coupling reagents, or high-boiling solvents. The stable -(1-ethoxyvinyl) moiety serves as a dual SAr-activating group and pyridine -protecting group that can be cleaved under thermal, acidic, or oxidative conditions.
View Article and Find Full Text PDFSelective hydrolysis of α-oxo ketene ,-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides.
Beilstein J Org Chem
September 2024
College of Chemistry, Baicheng Normal University, Baicheng, Jilin 137000, China.
An eco-friendly selective hydrolysis of chain α-oxo ketene ,-acetals in water for the switchable synthesis of β-keto thioesters and β-keto amides is reported. In refluxing water, the hydrolysis reactions of α-oxo ketene ,-acetals in the presence of 1.0 equiv of dodecylbenzenesulfonic acid effectively afforded β-keto thioesters in excellent yield, while β-keto amides were successfully obtained in excellent yield when the hydrolysis reactions were carried out in the presence of 3.
View Article and Find Full Text PDFRadical Cascade Reaction of Heterocyclic Ketene Aminals with Thiocyanates Promoted by Visible Light: Synthesis of Functionalized Fused 2-Iminothiazolines.
J Org Chem
September 2024
Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, P. R. China.
Herein, a visible-light-promoted radical cascade cyclization of heterocyclic ketene aminals (HKAs) and thiocyanates was developed to access functionalized fused 2-iminothiazolines. This novel cascade reaction can be realized under only visible-light irradiation without the help of external photocatalysts, oxidants, and additives. These multicomponent cascade reactions demonstrate excellent selectivity for the -isomers and ensure the formation of the products only in their isomeric form.
View Article and Find Full Text PDFCycloaddition and Skeleton Rearrangement of Heterocyclic Ketene Aminals (HKAs) with 1-Diazonaphthalen-2(1)-ones for the Synthesis of Functionalized 1,2,3-Triazoles.
Org Lett
August 2024
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P. R. China.
We developed a protocol for the synthesis of highly functionalized 5,6-dihydro-imidazo[1,2-][1,2,3]triazole derivatives - (DHITs) from 1-diazonaphthalen-2(1)-one derivatives with heterocyclic ketene aminals (HKAs). This strategy involved cycloaddition and skeletal rearrangement entailing the heating of a mixture of substrates with HKAs - and THF without any catalyst. As a result, a series of DHITs - were produced by cleaving one bond (1 C═N bond) and forming three bonds (1 N-N and 2 C-N bonds) in a single step.
View Article and Find Full Text PDFNitrones are widely used as 1,3-dipoles in organic synthesis, but control of their reactions is not always easy. This review outlines our efforts to make the reactions of nitrones more predictable and easier to use. These efforts can be categorized into (1) 1,3-nucleophilic addition reaction of ketene silyl acetals to nitrones, (2) geometry-controlled cycloaddition of C-alkoxycarbonyl nitrones, (3) stereo-controlled cycloaddition using double asymmetric induction, and (4) generation of nitrones by N-selective modification of oximes.
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!