An efficient and transition-metal-free method for the synthesis of the structurally diversified trifluoroethylthiol phenanthridines and 3,4-dihydroisoquinolines is described. Various 2-isothiocyanobiaryls and aryl alkyl isothiocyanates reacted with phenyl(2,2,2-trifluoroethyl)iodonium triflate in CHCl in the presence of trifluoromethanesulfonic acid at 40 °C to form the corresponding trifluoroethylation/cyclization products in good to quantitative yields. This work represents the first construction of trifluoroethylthiol phenanthridine and isoquinoline derivatives from isothiocyanates in the absence of transition-metal catalysts by a one-pot procedure.
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http://dx.doi.org/10.1021/acs.orglett.8b02793 | DOI Listing |
Pharmaceuticals (Basel)
January 2025
Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Str., 52428 Jülich, Germany.
The radiotracer [F]JK-PSMA-7, a prostate cancer imaging agent for positron emission tomography (PET), was previously synthesized by indirect radiofluorination using an F-labeled active ester as a prosthetic group, which had to be isolated and purified before it could be linked to the pharmacologically active Lys-urea-Glu motif. Although this procedure could be automated on two-reactor modules like the GE TRACERLab FX2N (FXN) to afford the tracer in modest radiochemical yields (RCY) of 18-25%, it is unsuitable for cassette-based systems with a single reactor. To simplify implementation on an automated synthesis module, the radiosynthesis of [F]JK-PSMA-7 was devised as a one-pot, two-step reaction.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry, Hunter College, The City University of New York, 695 Park Ave., New York, NY 10065, USA.
Using methods of DFT, we investigated the effect of electron withdrawing and electron donating groups on the relative stability of tentative glycosyl donor reaction intermediates. The calculation shows that by changing the stereoelectronic properties of the protecting group, we can influence the stability of the dioxolenium type of intermediates by up to 10 kcal mol, and that by increasing nucleophillicity of the 4--Bz group, the dioxolenium intermediate becomes more stable than a triflate-donor pair. We exploited this mechanism to design galactosyl donors with custom protecting groups on O2 and O4, and investigated the outcome of the reaction with cyclohexanol.
View Article and Find Full Text PDFNanoscale
January 2025
Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
Identifying facile strategies for hierarchically structuring crystalline porous materials is critical for realizing diffusion length scales suitable for broad applications. Here, we elucidate synthesis-structure-function relations governing how room temperature catalytic conditions can be exploited to tune covalent organic framework (COF) growth and thereby access unique hierarchical morphologies without the need to introduce secondary templates or structure directing molecules. Specifically, we demonstrate how scandium triflate, an efficient catalyst involved in the synthesis of imine-based COFs, can be exploited as an effective growth modifier capable of selectively titrating terminal amines on 2D COF layers to facilitate anisotropic crystal growth.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Chemical Engineering, Chung-Ang University (CAU), Seoul 06974, Republic of Korea. Electronic address:
We investigate the effects of water-processable celluloses on the charge-transport properties in the conducting polymer composites and their solid-state organic electrochemical transistors (OECTs). Water-soluble methyl cellulose (MC) and water-dispersible cellulose nanofiber (CNF) are blended with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) in solution and used as a conductive channel. Both cellulose-PEDOT:PSS composites show fibrillar structures in thin films with respective dimensions of cellulose.
View Article and Find Full Text PDFBeilstein J Org Chem
January 2025
Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria, Via Valleggio 9, 22100, Como, Italy.
This review reports the achievements in copper(II) triflate-catalyzed processes concerning the multicomponent reactions, applied to the synthesis of acyclic and cyclic compounds. In particular, for the heteropolycyclic systems mechanistic insights were outlined as well as cycloaddition and aza-Diels-Alder reactions were included. These strategies have gained attention due to their highly atom- and step-economy, one-step multi-bond forming, mild reaction conditions, low cost and easy handling.
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