Reported is a novel two-step ring-expansion strategy for expeditious synthesis of all ring sizes of synthetically challenging (hetero)aryl-fused medium-sized lactams from readily available 5-8-membered cyclic ketones. This step-economic approach features a remote radical (hetero)aryl migration from C to N under visible-light conditions. Broad substrate scope, good functional-group tolerance, high efficiency, and mild reaction conditions make this procedure very attractive. In addition, this method also provides expedient access to 13-15-membered macrolactams upon an additional one-step manipulation. Mechanistic studies indicate that the reaction involves an amidyl radical and is promoted by acid.
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http://dx.doi.org/10.1002/anie.201808890 | DOI Listing |
Nat Chem
December 2024
Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
Saturated N-heterocycles are ubiquitous structures among natural products and biologically active compounds. Therefore, the development of synthetic methods for the construction of N-heterocycles is of great importance in the synthetic community. Altering the ring system of these motifs to analogues with different ring sizes by employing molecular editing techniques would be highly appealing in medicinal chemistry.
View Article and Find Full Text PDFJ Infect Chemother
January 2025
Department of Pharmacy, Saiseikai Futsukaichi Hospital, Fukuoka, Japan.
Background: Efforts to promote antimicrobial stewardship aimed at reducing antimicrobial resistance are necessary regardless of hospital scale owing to delays in new antimicrobial development. We aimed to evaluate the effects of pharmacist-driven interventions on broad-spectrum antimicrobial usage and the prognosis of patients with bacteremia in a medium-sized hospital lacking infectious disease physicians and a microbiology laboratory.
Methods: This single-center, retrospective, pragmatic, quasi-experimental study was conducted to compare pre- and post-intervention effects at Saiseikai Futsukaichi Hospital.
PLoS One
May 2024
Centro de Ciencias Genómicas, Programa de Genómica Evolutiva, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
The blaNDM-1 gene and its variants encode metallo-beta-lactamases that confer resistance to almost all beta-lactam antibiotics. Genes encoding blaNDM-1 and its variants can be found in several Acinetobacter species, and they are usually linked to two different plasmid clades. The plasmids in one of these clades contain a gene encoding a Rep protein of the Rep_3 superfamily.
View Article and Find Full Text PDFMedium-sized 5- and 6-membered ring lactams are molecules with remarkable stability, in contrast to smaller β-lactams. As monomers, they grant access to nylon-4 and nylon-5, which are alternative polyamides to widespread caprolactam-based nylon-6. Chemical hydrolysis of monocyclic γ- and δ-lactams to the corresponding amino acids requires harsh reaction conditions and up to now, no mild (enzymatic) protocol has been reported.
View Article and Find Full Text PDFOrg Biomol Chem
April 2024
Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
New methods are described that expand the scope of the Successive Ring Expansion (SuRE) with respect to synthetically challenging lactams. A protocol has been developed for use with 'unreactive' lactams, enabling SuRE reactions to be performed on subsrates that fail under previously established conditions. Ring expansion is also demonstarted on 'reactive' lactams derived from iminosugars for the first time.
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