N-Pyrazolylcarboxamides and N-pyrazolylureas represent promising lead compounds for the development of novel antileishmanial drugs. Herein, we report the late-stage diversification of 3-bromopyrazoles 10 A/B and 14 A by Pd-catalyzed Sonogashira and Suzuki-Miyaura cross coupling reactions. The electron-withdrawing properties of the cyano moiety in 4-position of the pyrazole ring limited the acylation of the primary amino moiety in 5-position. A large set of pyrazoles bearing diverse aryl and alkynyl substituents in 3-position was prepared and the antileishmanial and antitrypanosomal activity was recorded. The urea 38 lacking the electron withdrawing cyano moiety in 4-position and containing the large 4-benzylpiperidinoo moiety exhibited a modest antileishmanial (IC=19 μM) and antitrypanosomal activity (IC=7.9 μM)). However, its considerable toxicity against the PMM and MRC-5 cells indicates low selectivity, i. e. a small gap between the desired antiparasitic activity and undesired cytotoxicity of <2- to 4-fold.
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http://dx.doi.org/10.1002/cmdc.202400028 | DOI Listing |
J Org Chem
December 2024
Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
α-/β-Galactosylceramide (GalCer) and glucosylceramide (GlcCer) derivatives having a radical label at the 6--position suitable for electron paramagnetic resonance spectroscopic studies were synthesized by a diversity-oriented strategy that is highlighted by the efficient glycosylation of a lipid precursor and late-stage ceramide assembly to enable lipid diversification. The strategy was also utilized to synthesize natural α-/β-GalCers and GlcCers. Furthermore, the involved azido-intermediates are flexible platforms to access various other GalCer and GlcCer derivatives.
View Article and Find Full Text PDFAcc Chem Res
December 2024
Department of Chemistry, Northeast Normal University, Changchun 130024, China.
ConspectusIn the past decade, single-atom skeletal editing, which involves the precise insertion, deletion, or exchange of single atoms in the core skeleton of a molecule, has emerged as a promising synthetic strategy for the rapid construction or diversification of complex molecules without laborious synthetic processes. Among them, carbene-initiated skeletal editing is particularly appealing due to the ready availability and diverse reactivities of carbene species. The initial endeavors to modify the core skeleton of heteroarenes through carbon-atom insertion could date back to 1881, when Ciamician and Denstedt described the conversion of pyrroles to pyridines by trapping haloform-derived free carbene.
View Article and Find Full Text PDFChemistry
December 2024
Department of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria.
We present a comprehensive account on the evolution of a synthetic platform for a subfamily of ent-pimaranes. For the most complex member, norflickinflimiod C, five distinct strategies relying on either cationic or radical polyene cyclizations to construct the requisite tricyclic carbon scaffold were explored. Insights from early and late stage oxidative and reductive dearomatization studies ultimately led to a mild, rhodium-catalyzed arene hydrogenation for the final synthetic route.
View Article and Find Full Text PDFNat Commun
December 2024
Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Zhuhai, Zhuhai, 519088, PR China.
BMC Plant Biol
November 2024
College of Agriculture, Guizhou University, Guiyang, China.
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