[reaction: see text] We describe methodology for the in situ generation of reactive monosubstituted ketenes from acid chlorides through a shuttle deprotonation process using NaH as an inexpensive stoichiometric base and a crown ether cocatalyst. We have successfully applied this new procedure to the catalytic, asymmetric synthesis of beta-lactams and alpha-haloesters.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol0172525 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Reductive Carbon Materials: Tailoring Chemistry and Electronic Properties to Improve Sodium-Ion Batteries.
Angew Chem Int Ed Engl
January 2025
Max Planck Institute of Colloids and Interfaces, Colloid Chemistry, Am Mühlenberg 1, 14476, Potsdam, GERMANY.
The development of versatile strategies for preparing functional carbon materials is essential for advancing a wide range of applications in materials science. Precursor design plays a pivotal role in governing the chemistry and structure of carbon materials for target applications. In this work, we report the synthesis of Meldrum's acid derivatives through Knoevenagel condensation with aromatic heterocycles such as pyrrole, furan, and thiophene, which serve as precursors for carbonaceous materials with tailored chemical and electronic properties.
View Article and Find Full Text PDFAza-[4 + 2]-cycloaddition of benzocyclobutenones into isoquinolinone derivatives enabled by photoinduced regio-specific C-C bond cleavage.
Nat Commun
December 2024
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.
The activation of C-C bond of benzocyclobutenones under mild reaction conditions remains a challenge. We herein report a photoinduced catalyst-free regio-specific C1-C8 bond cleavage of benzocyclobutenones, enabling the generation of versatile ortho-quinoid ketene methides for aza-[4 + 2]-cycloaddition with imines, which offers a facile route to isoquinolinone derivatives, including seven family members of protoberberine alkaloids, gusanlung A, B, D, 8-oxotetrahydroplamatine, tetrahydrothalifendine, tetrahydropalmatine, and xylopinine. Furthermore, the catalytic enantioselective version of this strategy is also realized by merging synergistic photocatalysis and chiral Lewis acid catalysis.
View Article and Find Full Text PDF3-Diazopiperidine-2,4-diones as Convenient Precursors to Rare Polysubstituted Spiro Bis-β,γ-lactams and 2-Oxopyrrolidine-3-carboxylic Acid Derivatives via the Thermally Promoted Wolff Rearrangement.
J Org Chem
November 2024
Institute of Chemistry, Saint Petersburg State University, Saint Petersburg 199034, Russian Federation.
Herein, we describe a diastereoselective and straightforward synthetic approach to polysubstituted spirocyclic bis-lactams bearing both β- and γ-lactam cores with diverse substitution patterns. The method developed is based on a microwave-assisted Wolff rearrangement/Staudinger [2 + 2] cycloaddition sequence involving 3-diazopiperidine-2,4-diones and imines. The corresponding reaction tolerates a wide range of functionalities in both substrates, giving the target bis-lactams in generally high yields.
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 PDFSynthesis, Reactivity, and Bonding Analysis of a Tetracoordinated Nickel Carbene.
Chemistry
December 2024
Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.
Nickel carbenes are key reactive intermediates in the catalytic cyclopropanation of olefins and other reactions, but isolated examples are scarce and generally rely on low coordination numbers (≤3) to stabilize the metal-ligand multiple bond. Here we report the isolation and characterization of a stable tetracoordinated nickel carbene bearing a triphosphine pincer ligand. Its nucleophilic character is evidenced by reaction with acids, and it can transfer the carbene fragment to CO to form a ketene.
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!