Synthesis, antimicrobial, anti-cancer and in silico studies of new urea derivatives

The reaction of an alkyl or aryl isocyanates with some primary amines in acetonitrile at room temperature afforded the corresponding alkyl- and aryl-urea derivatives. All the prepared urea compounds have been elucidated by FTIR, NMR, and elemental analysis. The compounds 1 and 3 were confirmed by single-crystal X-ray diffraction. The 4-tolylsulfonyl isocyanate reacted with the aryl amines 1, 2, 3, and 2,4-dichloroaniline to afford the corresponding sulfonylurea derivatives 5-8. Likewise, the reaction of the isocyanates with 2,4-dichloroaniline, 5-methyl isoxazole-3-amine, and 2-aminothiazole derivatives gave the corresponding urea derivatives 9-17. All the prepared compounds 5-17 were tested in vitro as anti-microbial and anti-HepG2 agents. Moreover, analyzing gene expression of TP53-exon4 and TP53-exon7, DNA damage values, and DNA fragmentation percentages have been discussed. The compounds 5 and 8 recorded the highest activity against the tested microbial strains with maximum activity against C. albicans (50 mm) and B. mycoides (40 mm), respectively. The compounds 5 inhibited the growth of E. coli, S. aureus, and C. Albicans at the MIC level of 0.0489 µM, while the compound 8 was able to inhibit the visible growth of E. coli and C. albicans at MIC value of 3.13 µM and S. aureus at 0.3912 µM. In the same line, compound 5 showed the best cytotoxic activity against the HepG2 cell line (IC₅₀ = 4.25 µM) compared to 5 fluorouracil with IC₅₀ = 316.25 µM. Expression analysis of liver cancer related to a gene including TP53-exon4 and TP53-exon7 was used in HepG2 Liver cancer cell lines using RT-qPCR. The expression values of TP53-exon4 and TP53-exon7 genes were decreased. The DNA damage values and DNA fragmentation percentages were increased significantly (P < 0.01) in the treated HepG2 (5) sample compared with the negative control. Docking studies were performed for the synthetic compounds against 2 bacterial proteins (DNA gyrase subunit B, and penicillin binding protein 1a) that are known targets for some antibiotics, and one cell division protein kinase 2 (CDK2) as target for anticancer drugs.

Synthesis and characterization of 2-t-butylimino-functionalized indolyl rare-earth metal amido complexes for the catalytic addition of terminal alkynes to carbodiimides: the dimeric complexes with the alkynide species in the μ–η1:η2 bonding modes

Dimeric complexes [(μ–η¹:η²-RCC)REL2]₂ (L = 2-(^tBuNCH)C₈H₅N), with alkynyl in the μ–η¹:η² modes, were isolated in the study of the catalytic reaction.

Synthesis and structural characterization of four di-chlorido-bis-(cyclo-propyl-alkynyl-amidine)-metal complexes

Deliberate hydrolysis of lithium cyclo-propyl-alkynylamidinates, Li[c-C3H5-C≡C(NR')2] [R' = i Pr, Cy = cyclo-hex-yl)], afforded the hitherto unknown neutral cyclo-propyl-alkynyl-amidine derivatives c-C3H5-C≡C-C(NR')(NHR') [R' = i Pr (1), Cy (2)]. Subsequent reactions of 1 or 2 with metal(II) chlorides, MCl2 (M = Mn, Fe, Co), provided the title complexes di-chlorido-bis-(3-cyclo-propyl-N,N'-diisopropyl-prop-2-ynamidine)-manganese(II), [MnCl2(C12H20N2)2], (3), di-chlorido-bis-(3-cyclo-propyl-N,N'-diisopropyl-prop-2-ynamidine)-iron(II), [FeCl2(C12H20N2)2], (4), di-chlorido-bis-(N,N'-di-cyclo-hexyl-3-cyclo-propyl-prop-2-ynamidine)-iron(II), [FeCl2(C18H28N2)2], (5), and di-chlorido-bis-(N,N'-di-cyclo-hexyl-3-cyclo-propyl-prop-2-ynamidine)-cobalt(II), [CoCl2(C18H28N2)2], (6), or more generally MCl2[c-C3H5-C≡C-C(NR')(NHR')]2 [R' = i Pr, M = Mn (3), Fe (4); R' = Cy, M = Fe (5), Co (6)] in moderate yields (30-39%). Besides their spectroscopic data (IR and MS) and elemental analyses, all complexes 3-6 were structurally characterized. The two isopropyl-substituted complexes 3 and 4 are isotypic, and so are the cyclo-hexyl-substituted complexes 5 and 6. In all cases, the central metal atom is coordinated by two Cl atoms and two N atoms in a distorted-tetra-hedral fashion, and the structure is supported by intra-molecular N-H⋯Cl hydrogen bonds.

Simple ZnEt2as a catalyst in carbodiimide hydroalkynylation: structural and mechanistic studies

Simple ZnEt₂is an efficient catalyst for the addition of terminal alkynes to carbodiimides, through amidinate complexes, and consecutive isocyanate addition and intramolecular cyclohydroamination.

Crystal structures of two ytterbium(III) complexes comprising alkynylamidinate ligands

Two ytterbium(III) complexes comprising alkynylamidinate ligands, namely bis-(η5-cyclo-penta-dien-yl)(3-cyclo-propyl-N,N'-diiso-propyl-propynamidinato-κ2N,N')ytterbium(III), [Yb(C5H5)2(C12H19N2)] or Cp2Yb[( i Pr2N)2C-C≡C-c-C3H5] (1) and tris-(3-phenyl-N,N'-di-cyclo-hexyl-propynamidinato-κ2N,N')ytterbium(III), [Yb(C21H27N2)3] or Yb[(CyN)2C-C≡C-Ph]3 (Cy = cyclo-hex-yl) (2) have been synthesized and structurally characterized. Both complexes are monomers; for complex 2, the contribution to the scattering from highly disordered toluene solvent molecules in these voids was removed with the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9-18] in PLATON. The stated crystal data for Mr, μ etc. do not take these into account.

Five different types of η8-cyclooctatetraenyl-lanthanide half-sandwich complexes from one ligand set, including a “giant neodymium wheel”

Using one ligand set, five different types of η⁸-cyclooctatetraenyl-lanthanide half-sandwich complexes, including a “giant neodymium wheel”, have been prepared and structurally characterized.