The 2-(2-isocyanatophenyl)ethyl radical was generated from the corresponding bromide with tributyltin and tris(trimethylsilyl)silyl radicals and shown to ring close in the 6-endo-mode to afford 3,4-dihydro-1H-quinolin-2-one as the major product. Cyclization in the 5-exo-mode to produce 2,3-dihydroindole-1-carbaldehyde, after hydrogen abstraction, was a minor reaction. Rate constants for the two processes were estimated and compared with reaction enthalpies computed by the DFT method.
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http://dx.doi.org/10.1021/jo034002o | DOI Listing |
Chem Commun (Camb)
January 2025
Lunan Institute of Intelligent Biomedical Engineering, College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang, 277160, P. R. China.
A silver-catalyzed cross coupling of cyclic aldimines and α-imino-oxy acids has been developed. The solvent-dependent reaction could selectively deliver either cyclic imine moiety retained nitriles or ring-opened oxonitriles in moderate yields. The mechanistic studies show that the reaction undergoes a radical pathway.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany.
The persistent organic radical 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) protects its NO radical center by four methyl groups. Two of them are arranged tightly (t) on one side of the six-membered puckered heterocycle, and the other two more openly (o) on the other side. It is shown by OH stretching infrared spectroscopy in heated supersonic jet expansions that the hydrogen bond and aromatic ring of a first solvating benzyl alcohol have almost no preference for either side.
View Article and Find Full Text PDFChem Sci
January 2025
Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir Prelog Weg 5 8093 Zurich Switzerland
The labile end-groups inherent to many controlled radical polymerization methodologies, including atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization, can trigger the efficient chemical recycling of polymethacrylates yielding high percentages of pristine monomer. Yet, current thermal solution ATRP and RAFT depolymerization strategies require relatively high temperatures ( 120-170 °C) to proceed, with slower depolymerization rates, and moderate yields often reported under milder reaction conditions ( lower temperatures). In this work, we seek to promote the low temperature RAFT depolymerization of polymethacrylates regulating the Z-group substitution of dithiobenzoate.
View Article and Find Full Text PDFNat Chem
January 2025
Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen, China.
The substitution of an aromatic ring with a C(sp)-rich bicyclic hydrocarbon, known as bioisosteric replacement, plays a crucial role in modern drug discovery. Substituted bicyclo[1.1.
View Article and Find Full Text PDFMol Biochem Parasitol
January 2025
Post-graduate Program in Pharmaceutical Sciences, Federal University of Ceará, Fortaleza - CE, Brazil; Fundação Oswaldo Cruz, Fiocruz, Fiocruz Ceará, Eusébio - CE, Brazil; Northeast Network of Biotechnology (RENORBIO), State University of Ceará (UECE), Fortaleza - CE, Brazil.
Globally, an estimated 1 billion people reside in endemic areas, and over 12 million individuals are infected with leishmaniasis. Despite its prevalence, leishmaniasis continues to be a neglected disease, mainly affecting underdeveloped countries. In Brazil, the available treatments are pentavalent antimonials and Amphotericin B, which are outdated, toxic, require prolonged parenteral administration and have limited efficacy.
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