Tertiary cyclopropanols react rapidly with Togni reagent in methanol at room temperature in the presence of catalytic amounts (3 mol%) of CuCl affording β-trifluoromethyl ketones in 65-73% isolated yields. Ring opening in 1,2-dialkylsubstituted cyclopropanols gives a mixture of isomeric β-trifluoromethyl ketones in about 50% combined yield.
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http://dx.doi.org/10.1039/c5cc02386f | DOI Listing |
Dalton Trans
January 2025
Anhui Province Engineering Laboratory of Advanced Building Materials, College of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, 230601, China.
A universal and green catalytic system for the hydrogenation of unsaturated aldehydes and ketones into the corresponding alcohols with the CC bonds retained under atmospheric hydrogen pressure in the water phase was realized by -functionalized amino ligand-stabilized ruthenium complexes (-PPhCHNHMe)[(CHNHR)]RuCl (R = H, Me, Et) and (-PPhCHNMe)[(CHNHEt)]RuCl with wide substrate compatibility and excellent functionality tolerance. The structural synergism between -PPhCHNHMe and (CHNHEt) achieves the enhanced performance, with a positive correlation with the electron density of the amino ligand.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
An unprecedented synergistic copper- and amine-catalyzed cyclization of enynone is reported. This reaction features an efficient and straightforward construction of multisubstituted tetralone through an amine-assisted regioselective oxygen atom transfer process and stereoselective intramolecular Michael addition cyclization. Under dehydrative reaction conditions, the synthesis of tetrahydronaphthylimine derivatives with ketone group tolerance is achieved, which could be challenging via traditional methods.
View Article and Find Full Text PDFRSC Adv
January 2025
Department of Organic Chemistry, University of Debrecen Egyetem Square 1 Debrecen 4032 Hungary
Domino Knoevenagel-cyclization reactions of styrene substrates, containing an -(-formyl)aryl subunit, were carried out with -substituted 2-cyanoacetamides to prepare tetrahydro-4-pyrano[3,4-]quinolone and hexahydrobenzo[]phenanthridine derivatives by competing IMHDA and IMSDA cyclization, respectively. The diastereoselective IMHDA step with α,β-unsaturated amide, thioamide, ester and ketone subunits as a heterodiene produced condensed chiral tetrahydropyran or thiopyran derivatives, which in the case of Meldrum's acid were reacted further with amine nucleophiles in a multistep domino sequence. In order to simplify the benzene-condensed tricyclic core of the targets and get access to hexahydro-1-pyrano[3,4-]pyridine derivatives, a truncated substrate was reacted with cyclic and acyclic active methylene reagents in diastereoselective Knoevenagel-IMHDA reactions to prepare novel condensed heterocyclic scaffolds.
View Article and Find Full Text PDFIn this research, we report a simple fluorescent probe designed to detect thallium(iii) ions (Tl) in artificial urine samples. The Tl signaling probe (TP-1) was readily prepared from 2-acetyl-6-methoxynaphthalene and hydrazine. In a pH 4.
View Article and Find Full Text PDFJ Org Chem
January 2025
Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) and Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
Described herein is our computational study to rationalize the stereoselective epimerization of α,α'--disubstituted oxolane and oxetane ketones and to the corresponding α,α'- ketones and reported in our previous total syntheses of (+)-3-()-isolaureatin () and (+)-3-()-laureatin (). Density functional theory (DFT) calculations using appropriately truncated models revealed that the α,α'- ketones are more stable than the α,α'- ketones, in very good agreement with experimental results. The computational results showed that the isomer with a longer interatomic distance between the two ring oxygen atoms was lower in energy, which suggested the presence of repulsive interactions between those oxygen atoms.
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