Search results for "kemiallinen synteesi"
showing 10 items of 92 documents
Synthesis, X-ray Single-Crystal Analysis, and Anticancer Activity Evaluation of New Alkylsulfanyl-Pyridazino[4,5-b]indole Compounds as Multitarget In…
2022
The alkylation of 3,5-dihydro-4H-pyridazino[4,5-b]indole-4-thione with benzyl bromide, ethyl chloroacetate, and allyl bromide in the presence of potassium carbonate (K2CO3) yielded new alkylsulfanylpyridazino[4,5-b]indole derivatives (i.e., compounds 4–6). Hydrazinolysis of ester 6 resulted in hydrazide 7. The structure of compound 6 was verified by X-ray single-crystal analysis. Among the synthesized compounds, compound 6 exhibited the most promising cytotoxicity toward MCF-7 cells with an IC50 value of 12 µM. It showed potential inhibition activity toward EGFR, PI3K, and AKT in MCF-7 cells, with 0.26-, 0.49-, and 0.31-fold reductions in concentration compared to an untreated c…
Uranocenium: Synthesis, Structure, and Chemical Bonding
2019
Abstraction of iodide from [(η5 -C5 i Pr5 )2 UI] (1) produced the cationic uranium(III) metallocene [(η5 -C5 i Pr5 )2 U]+ (2) as a salt of [B(C6 F5 )4 ]- . The structure of 2 consists of unsymmetrically bonded cyclopentadienyl ligands and a bending angle of 167.82° at uranium. Analysis of the bonding in 2 showed that the uranium 5f orbitals are strongly split and mixed with the ligand orbitals, thus leading to non-negligible covalent contributions to the bonding. Investigation of the dynamic magnetic properties of 2 revealed that the 5f covalency leads to partially quenched anisotropy and fast magnetic relaxation in zero applied magnetic field. Application of a magnetic field leads to domin…
Synthesis of C2-Symmetrical Bis-(β-Enamino-Pyran-2,4-dione) Derivative Linked via 1,6-Hexylene Spacer: X-ray Crystal Structures, Hishfeld Studies and…
2021
The synthesis of C2-symmetrical bis(β-enamino-pyran-2,4-dione) derivative 3 connected via 1,6-hexylene linker was reported for the first time. X-ray structures and Hirshfeld studies of the new bis- β-enamino-pyran-2,4-dione derivative 3 along with two structurally related pyran-2,4-dione derivatives 2a,b were discussed. A comparative analysis of the different intermolecular contacts affecting the crystal stability was presented. Generally, the H…H, O…H, and H…C interactions are common in all compounds and are considered the most abundant contacts. In addition, DFT calculations were used to compute the electronic properties as well as the 1H and 13C NMR spectra of the studied systems. All co…
Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols
2021
A library of pinane-based 2-amino-1,3-diols was synthesised in a stereoselective manner. Isopinocarveol prepared from (−)-α-pinene was converted into condensed oxazolidin-2-one in two steps by carbamate formation followed by a stereoselective aminohydroxylation process. The relative stereochemistry of the pinane-fused oxazolidin-2-one was determined by 2D NMR and X-ray spectroscopic techniques. The regioisomeric spiro-oxazolidin-2-one was prepared in a similar way starting from the commercially available (1R)-(−)-myrtenol (10). The reduction or alkaline hydrolysis of the oxazolidines, followed by reductive alkylation resulted in primary and secondary 2-amino-1,3-diols, which underwent a reg…
Control of N-Heterocyclic Carbene Catalyzed Reactions of Enals: Asymmetric Synthesis of Oxindole-γ-Amino Acid Derivatives.
2017
A strategy to control the switch between a non‐cycloaddition reaction and a cycloaddition reaction of enals, using N‐heterocyclic carbene (NHC) catalyisis, has been developed. The new scalable protocol leads to γ‐amino‐acid esters bearing a tetrasubstituted stereocenter in good yields and high stereoselectivities by homo‐Mannich reactions of enals and isatin‐derived ketimines. By simply changing the N‐ketimine substituent to an ortho‐hydroxy phenyl group, the corresponding spirocyclic oxindolo‐γ‐lactams are obtained. peerReviewed
Catalytic Enantioselective Total Synthesis of (+)-Lycoperdic Acid.
2020
A concise enantio- and stereocontrolled synthesis of (+)-lycoperdic acid is presented. The stereochemical control is based on iminium-catalyzed Mukaiyama–Michael reaction and enamine-catalyzed organocatalytic α-chlorination steps. The amino group was introduced by azide displacement, affording the final stereochemistry of (+)-lycoperdic acid. Penultimate hydrogenation and hydrolysis afforded pure (+)-lycoperdic acid in seven steps from a known silyloxyfuran. peerReviewed
Synthesis, structure and reaction chemistry of a nucleophilic aluminyl anion.
2018
The reactivity of aluminium compounds is dominated by their electron deficiency and consequent electrophilicity; these compounds are archetypal Lewis acids (electron-pair acceptors). The main industrial roles of aluminium, and classical methods of synthesizing aluminium–element bonds (for example, hydroalumination and metathesis), draw on the electron deficiency of species of the type AlR3 and AlCl31,2. Whereas aluminates, [AlR4]−, are well known, the idea of reversing polarity and using an aluminium reagent as the nucleophilic partner in bond-forming substitution reactions is unprecedented, owing to the fact that low-valent aluminium anions analogous to nitrogen-, carbon- and boron-centred…
N‐Heterocyclic Carbene Catalyzed Asymmetric Synthesis of Pentacyclic Spirooxindoles via [3+3] Annulations of Isatin‐Derived Enals and Cyclic N‐Sulfon…
2019
A Multi-Component Reaction towards the Development of Highly Modular Hydrogelators
2018
Herein we report a multi‐component reaction approach for the development of a new class of hydrogelators based on the OxoTriphenylHexanOate (OTHO) backbone. A focused library of OTHOs has been synthesized and their hydrogelation features evaluated. The two most potent hydrogelators were studied by rheology revealing different stiffness, appearances and thixotropic behavior of the gels. The new gelators showcase the versatility of the OTHO backbone as a platform for the design of functionalized hydrogels with tunable gel properties. peerReviewed
Synthesis and Characterisation of Chiral Triazole-Based Halogen-Bond Donors: Halogen Bonds in the Solid State and in Solution
2017
A general platform for the synthesis of various chiral halogen-bond (XB) donors based on the triazole core and the characterisation of factors that influence the strength of the halogen bond in the solid state and in solution are reported. The characterisation of XB donors in the solid state by X-ray crystallography and in solution by 1H NMR titration can be used to aid the design of new XB donors. We describe the first example of a XB between iodotriazoles and thioureas in solution. In addition, the enantiodiscrimination of acceptors in solution through halogen-bond participation is described.