Reactions of group 4 metallocene sources with 2-substituted pyridines were investigated to evaluate their coordination type between innocent and reductive dearomatisation as well as to probe the possibility for couplings. A dependence on the cyclopentadienyl ligands (Cp, Cp*), the metals (Ti, Zr), and the substrates (2-phenyl-, 2-acetyl-, and 2-iminopyridine) was observed. While 2-phenylpyridine is barely reactive, 2-acetylpyridine reacts vigorously with the Cp-substituted complexes and selectively with their Cp* analogues. With 2-iminopyridine, in all cases selective reactions were observed. In the isolated [Cp Ti], [Cp Zr], and [Cp* Zr] compounds the substrate coordinates by its pyridyl ring and the unsaturated side-chain. Subsequently, the pyridine was dearomatised, which is most pronounced in the [Cp* Zr] compounds. Using [Cp* Ti] leads to the unexpected paramagnetic complexes [Cp* Ti (N,O-acpy)] and [Cp* Ti (N,N'-impy)]. This highlights the non-innocent character of the pyridyl substrates.
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http://dx.doi.org/10.1002/chem.201504411 | DOI Listing |
J Org Chem
October 2024
Department of Chemistry and Biochemistry, Texas State University, 601 University Dr., San Marcos, Texas 78666, United States.
Herein, we describe a novel reaction between C-2-substituted indoles and 2-nitroacetophenones leading to a variety of indole-containing heterocyclic scaffolds. At 60 °C in AcOH with HSO as catalyst, C-2 aryl indoles give 3-(2-nitrovinyl)-indoles with high or geometric selectivity depending on the type of substrate utilized. These compounds undergo an electrocyclization process in a sealed vial in a microwave apparatus in DMF at 250 °C to give benzo[]carbazoles and naphtho[2,1-]carbazoles depending on whether the C-2 aromatic moiety is phenyl or naphthyl.
View Article and Find Full Text PDFCurr Drug Discov Technol
June 2024
Department of Pharmaceutical Chemistry, Pune District Education Association's Seth Govind Raghunath Sable College of Pharmacy, Saswad, Pune-412 301, Maharashtra, India.
Background: The development of antimicrobial agents is crucial for several reasons, primarily to combat infectious diseases and to address the growing threat of antimicrobial resistance. The need for the contin-ued development of antimicrobial drugs persists despite the presence of many existing drugs for several reasons viz; emerging new pathogens and diseases, reistance to existing drug and propogation of multi-drug resistance to existing drugs.
Objective: The objective of the study was to synthesize and evaluate the antimicrobial potential of newly synthesized benzothiazole derivatives.
Mol Immunol
June 2024
Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti 66100, Italy. Electronic address:
Macrophage polarization towards the M1 phenotype under bacterial product-related exposure (LPS) requires a rapid change in gene expression patterns and cytokine production along with a metabolic rewiring. Metabolic pathways and redox reactions are such tightly connected, giving rise to an area of research referred to as immunometabolism. A role in this context has been paid to the master redox-sensitive regulator Nuclear factor erythroid 2-related factor 2 (Nrf2) and to the 5'-ectonucleotidase CD73, a marker related to macrophage metabolism rearrangement under pro-inflammatory conditions.
View Article and Find Full Text PDFJ Am Chem Soc
March 2024
Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg Germany.
The synthesis of pyridines from dinitrogen in homogeneous solution is known to be challenging considering that an N cleavage step needs to be combined with two N-C coupling steps. Herein, a tungsten complex bearing a tailor-made 2,2'-(BuAs)-substituted tolane ligand scaffold was shown to split N to afford the corresponding tungsten nitride, which is not the case for the corresponding (PrAs)-substituted derivative. The former nitride was then reacted with 2,4,6-trimethylpyrylium triflate, which led to the formation of a tungsten oxo complex, along with collidine.
View Article and Find Full Text PDFFuture Med Chem
April 2024
Department of Medicinal Chemistry, Faculty of Pharmacy, Minia University, 61519, Egypt.
The purpose of this work is to create and synthesize a new class of chemicals: 3-cyano-2-substituted pyridine compounds with expected multitarget inhibition of histone deacetylase (HDAC) and tubulin. The target compounds ( and ) were synthesized utilizing 6-(4-methoxyphenyl)-2-oxo-4-(3,4,5-trimethoxyphenyl)-3-cyanopyridine, with various linkers and zinc-binding groups (ZBGs). Most of the tested compounds showed promising growth inhibition, and hydroxamic acid-containing hybrids possessed higher HDAC inhibition than other ZBGs.
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