Herein, we report a palladium-catalyzed dehydrogenative cross-coupling of indoles with cyclic enones to give β-indolyl cyclic enones under mild and neutral reaction conditions. The key to the success is to explore a mild condition, which ensures the indole C-H activation and subsequent β-hydride elimination through rapid enolization isomerization of Pd(II)-enolate while suppressing other undesired side reactions. Synthetic utility has also been demonstrated in the flexible transformation of the coupling products to -phenols and benzo[a]carbazoles.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.0c01763 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Defluorinative Diazolation-Cyclization Relay for Synthesis of Furan-Bridged Triheterocycles and Colorimetric Sensor Application.
Chemistry
December 2024
Technical Institute of Fluorochemistry, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, China.
Polyaromatics, as the assembly of diverse cyclic π-systems, exhibit unique physicochemical properties when compared to their individual constituents. In this study, we developed a strategic connection of two azacycles via a furan bridge through a defluorinative diazolation-cyclization reaction of trifluoromethyl enones and N-heterocycles. A range of modular 2,4-furan-bridged triheterocycles (FBTHs), featuring a C3-trifluoromethyl group, was synthesized with broad substrate scope and good regioselectivity under transition metal-free conditions.
View Article and Find Full Text PDFIsochroman-3,4-dione and Tandem Aerobic Oxidation of 4-Bromoisochroman-3-one in the Highly Regio- and Diastereoselective Diels-Alder Reaction for the Construction of Bridged Polycyclic Lactones.
J Org Chem
December 2024
Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, 84084 Fisciano, SA, Italy.
Herein we report two processes facilitated by diisopropylethylamine (DIPEA) for the synthesis of novel bridged polycyclic molecule analogues to natural products. The use of 4-bromoisochroman-3-one initiated an autoxidation reaction, followed by a Diels-Alder cycloaddition in the presence of electron-deficient dienophiles. Mechanistic studies revealed isochromane-3,4-dione as a key intermediate, which undergoes in situ dienolization/dearomatization followed by a [4 + 2] cycloaddition.
View Article and Find Full Text PDFAsymmetric Construction of Chiral 2-Azetines and Axially Chiral Tetrasubstituted Allenes Via Phosphine Catalysis.
Angew Chem Int Ed Engl
January 2025
Department of Chemistry, China Agricultural University, 2 West Yuanmingyuan Road, Beijing, 100193, P. R. China.
Chiral 2-azetines and allenes are highly valuable structural units in natural products and useful chemicals. However, enantioselective synthesis of both 2-azetines and allenes has been extremely challenging. Herein, we present asymmetric construction of chiral 2-azetines (70-98 % yields and up to 96 % ee) through chiral phosphine-catalyzed [2+2] annulation of yne-enones with sulfamate-derived cyclic imines.
View Article and Find Full Text PDFNickel-Catalyzed Reductive Alkenylation of Enol Derivatives: A Versatile Tool for Alkene Construction.
Acc Chem Res
November 2024
State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, China.
Article Synopsis
- - Ketone-to-alkene transformations are important in organic chemistry, and recent nickel-catalyzed reductive alkenylation reactions show promise for creating a variety of alkenes using different functional groups.
- - The authors' research started with coupling α-chloroboronates, then expanded to include a range of radical-inactive compounds, leading to the development of new strategies for cross-selectivity in various chemical reactions.
- - These advancements enable efficient synthesis of valuable products, including functionalized cycloalkenes and diverse alkenes, by broadening the types of enol derivatives used in the reactions, making the approach more accessible and practical.
Ring Expansion via One-Pot Conversion of Lactone Acetals to Cyclic Enones. Synthesis of (±)-1--Xerantholide.
Org Lett
October 2024
Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330-8262, United States.
Baeyer-Villiger oxidation of α-alkoxy ketones provides lactone acetals , which react with the lithium salts of dimethyl(alkyl) phosphonates in the presence of LaCl·2LiCl to provide cyclic enones in good to excellent yields after treatment with dilute aqueous potassium carbonate. Thus, five-, six-, and seven-membered lactones are converted to five-, six-, and seven-membered cyclic enones. The utility of this two-step ring expansion method is demonstrated in the synthesis of (±)-1--xerantholide from 5-methyl-2-cyclohexen-1-one.
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!