Search results for "kemiallinen synteesi"

N-(2,3,5,6-Tetrafluoropyridyl)sulfoximines : synthesis, X-ray crystallography, and halogen bonding

2020

In the presence of KOH, NH-sulfoximines react with pentafluoropyridine to give N-(tetrafluoropyridyl)sulfoximines (NTFP-sulfoximines) in moderate to excellent yields. Either a solution-based or a superior solvent-free mechanochemical protocol can be followed. X-Ray diffraction analyses of 26 products provided insight into the bond parameters and conformational rigidity of the molecular scaffold. In solid-state structures, sulfoximines with halo substituents on the S-bound arene are intermolecularly linked by C–X⋯O[double bond, length as m-dash]S (X = Cl, Br) halogen bonds. Hirshfeld surface analysis is used to assess the type of non-covalent contacts present in molecules. For mixtures of th…

Experimental and computational investigation on the formation pathway of [RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) from [RuCl2(CO)3]2 and E…

2022

The pathways to the formation of the series of [RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) complexes from [RuCl2(CO)3]2 and ERR′ have been explored experimentally in THF and CH2Cl2, and computationally by PBE0-D3/def2-TZVP calculations. The end-products and some reaction intermediates have been isolated and identified by NMR spectroscopy, and their crystal structures have been determined by X-ray diffraction. The relative stabilities of the [RuCl2(CO)2(ERR′)2] isomers follow the order cct > ccc > tcc > ttt ≈ ctc (the terms c/t refer to cis/trans arrangement of the ligands in the order of Cl, CO, and ERR′). The yields were rather similar in both solvents, but the reactions were signi…

The Monomeric Alanediyl : AlAriPr8 (AriPr8 = C6H-2,6-(C6H2-2,4,6-Pri3)2-3,5-Pri2) : An Organoaluminum(I) Compound with a One-Coordinate Aluminum Atom

2020

Reduction of the aluminum iodide AlI2AriPr8 (1; AriPr8 = C6H-2,6-(C6H2-2,4,6-Pri3)2-3,5-Pri2) with 5% w/w Na/NaCl in hexanes gave a dark red solution from which the monomeric alanediyl :AlAriPr8 (2) was isolated in ca. 28% yield as yellow-orange crystals. Compounds 1 and 2 were characterized by X-ray crystallography, electronic and NMR spectroscopy, and theoretical calculations. The Al atom in 2 is one-coordinate, and the compound displays two absorptions in its electronic spectrum at 354 and 455 nm. It reacts with H2 under ambient conditions to give the aluminum hydride {AlH(μ-H)AriPr8}2, probably via a weakly bound dimer of 2 as an intermediate. peerReviewed

A novel synthetic approach to pyran-2,4-dione scaffold production : microwave-assisted dimerization, cyclization, and expeditious regioselective conv…

2020

Here, we report a novel, green, simple, low-cost, and rapid methodology for the high-yield production of pyran-2,4-dione scaffolds under microwave irradiation. Regio- and stereoselective conversions of β-diketone systems into β-enaminones were achieved using 18 primary amines and four amino acid esters. Microwave-assisted further cyclization of 3-(β-substitutedvinyl)-6-phenyl-pyran-2,4-dione into 3-benzoyl-4,7-diphenyl-2H,5H-pyrano[4,3-b]pyran-2,5-dione via reaction with ethyl benzoyl acetate. peerReviewed

Atovakonin, parvakonin ja buparvakonin syntetiikka, rakennemääritys sekä lääketieteellinen käyttö

2008

Synthesis of silacyclopent-2-en-4-ols via intramolecular [2 + 2] photocycloaddition of benzoyl(allyl)silanes

2019

Organosilicon compounds are versatile units with a wide range of uses from medicinal chemistry to the field of organic electronics. An unprecedented method for the synthesis of novel diaryl-substituted silacyclopentenols via blue-light promoted intramolecular [2 + 2] photocycloaddition of acyl silanes is herein disclosed. Additionally, the present findings demonstrate the influence of the olefin substituents in controlling the regioselectivity of the intramolecular Paternò–Büchi reaction, providing silacycles different from previously reported ones. The high degree of functionalization of these compounds makes them attractive precursors to other synthetically challenging silacyclopentanes. …

Experimental and computational studies of unconventional main group compounds : stable radicals and reactive intermediates

2017

Ever since their discovery, radicals have intrigued the minds of experimental and theoretical chemists alike. While the vast majority of radicals are transient species, a large number of stable and persistent radicals are also known. This has enabled the use of radicals in different applications. For example, radicals are highly useful in chemical synthesis due to their selectivity and functional group tolerance. Detailed knowledge of the electronic structure of synthetic intermediates, both radical and non-radical, enables chemists to improve existing synthesis routes and to design completely new ones. This thesis is divided into two parts. The first part begins with an introduction to the…

Experimental and computational studies of transition metal complexes with polydentate amino- and amidophenolate ligands : synthesis, structure, react…

2013

Chelating polydentate ligands play a key role in several areas of modern coordination chemistry. They can be exploited, for example, in catalysis, bioinorganic chemistry, heavy metal abstraction and molecular magnetism. Furthermore, compounds of this type can be found in natural chemicals, commercial products and industrial applications. In this dissertation, several 3d, 4d and 5d transition metal complexes with polydentate amino- and amidophenolate ligands were prepared and their structure, reactivity and magnetic properties were studied with experimental and computational techniques. In the first part of the dissertation, the solid-state structure, reactivity and magnetic properties of 12…

Synthesis, Characterization, and Cytotoxicity of New Spirooxindoles Engrafted Furan Structural Motif as a Potential Anticancer Agent

2022

A new series of spirooxindoles based on ethylene derivatives having furan aryl moiety are reported. The new hybrids were achieved via [3 + 2] cycloaddition reaction as an economic one-step efficient approach. The final constructed spirooxindoles have four contiguous asymmetric carbon centers. The structure of 3a is exclusively confirmed using X-ray single crystal diffraction. The supramolecular structure of 3a is controlled by O···H, H···H, and C···C intermolecular contacts. It includes layered molecules interconnected weak C–H···O (2.675 Å), H···H (2.269 Å), and relatively short Cl···Br interhalogen interactions [3.4500(11)Å]. Using Hirshfeld analysis, the percentages of these intermolecul…

Optimizing the SYBR green related cyanine dye structure to aim for brighter nucleic acid visualization

2022

In recent years, the studies of RNA and its use for the development of RNA based vaccines have increased drastically. Although cyanine dyes are commonly used probes for studying nucleic acids, in a wide range of applications, there is still a growing need for better and brighter dyes. To meet this demand, we have systematically studied the structure of SYBR green-related cyanine dyes to gain a deeper understanding of their interactions with biomolecules especially how they interact with nucleic acids and the structural components which makes them strongly fluorescent. Herein, five new dyes were synthesized, and their photophysical properties were evaluated. Observations of photophysical cha…