The TfOH-mediated reactions of 2,4-diaryl-1,1,1-trifluorobut-3-yn-2-oles (CF₃-substituted diaryl propargyl alcohols) with arenes in CH₂Cl₂ afford 1,3-diaryl-1-CF₃-indenes in yields up to 84%. This new process for synthesis of such CF₃-indenes is complete at room temperature within one hour. The synthetic potential, scope, and limitations of this reaction were illustrated by more than 70 examples. The proposed reaction mechanism invokes the formation of highly reactive CF₃-propargyl cation intermediates that can be trapped at the two mesomeric positions by the intermolecular nucleophilic attack of an arene partner with a subsequent intramolecular ring closure.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321356 | PMC |
http://dx.doi.org/10.3390/molecules23123079 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Department of Chemistry, Fudan University, 220 Handan Rd., Shanghai, 200433, China.
Atropisomers with multiple stereogenic axes have attracted much attention due to their increasing significance in the fields of natural products, chiral materials, and drug discoveries. However, the catalytic stereoselective construction of axially chiral ring scaffolds with more than two axes on a single benzene ring remains a challenging task. Herein, we present an efficient method for synthesizing triaxially chiral polysubstituted naphthalene scaffolds via sequential Ni(II)-catalyzed Diels-Alder reaction of isobenzofurans and TfOH-promoted dehydrative aromatization reaction.
View Article and Find Full Text PDFJ Org Chem
June 2024
CAS Key Laboratory of High-Performance Synthetic Rubber and Its Composite Materials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
A straightforward synthesis of substituted β-aminoamides from α-arylamino-β-hydroxyacrylamides, α-arylamino-β-oxoamides, or their tautomeric mixture has been described. The ()-enol triflate intermediates are readily generated in situ from these substrates in the presence of triflic anhydride (TfO) and triethylamine (EtN) in a chemoselective manner and undergo triflic acid (TfOH)-promoted cyclization and ring-opening reactions with alcohols to deliver the desired products. The one-pot two-step synthetic protocol features the use of readily available starting materials, mild reaction conditions, high chemoselectivity, operational simplicity, and a wide range of synthetic potential of the products.
View Article and Find Full Text PDFChem Commun (Camb)
November 2023
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India.
A TfOH-promoted, metal-free protocol has been unveiled for the synthesis of spiro-furan quinazolinones employing alkynol urea derivatives utilizing alkynyl Prins cyclization reaction. This methodology produces highly functionalized spiro-heterocycles in excellent yields with exclusive -selectivity under ambient conditions. Furthermore, late-stage modifications incorporate bromide and acetyl functionalities into the synthesized spiro-heterocycles.
View Article and Find Full Text PDFMolecules
December 2022
Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China.
2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichiometric amounts of waste or require forcing azeotropic reflux conditions.
View Article and Find Full Text PDFChem Commun (Camb)
August 2022
School of Chemistry, University of Hyderabad, Hyderabad, Telangana 500046, India.
A metal-free approach to construct indole rings from vinylogous amides derived from -alkynylanilines involving a cyclization, retro-aza-Michael reaction and amine trapping cascade is reported here. This atom-economical transformation has been extended to synthesize benzofuran derivatives using analogous vinylogous esters derived from -alkynylphenols. The excellent stereochemical outcome of the double bond geometry in the products makes it attractive.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!