Physico-chemical properties important to drug discovery (pKa , LogP, and aqueous solubility), as well metabolic stability, were studied for a series of functionalized gem-difluorinated cycloalkanes compared those non-fluorinated acyclic counterparts evaluate the impact fluorination. It was found that influence CF2 moiety on acidity/basicity corresponding carboxylic acids amines defined by inductive effect fluorine atoms nearly same cyclic aliphatic compounds. Lipophilicity solubility...

Addition of anions derived from dialkyl methylphosphonates to (Ss)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine afforded (Ss,R) addition adducts in moderate good yield (53–75%) with excellent diastereoselectivity (94–95% de). After selective removal the N-sulfinyl group, dipeptides containing enantiomerically pure diethyl 2-amino-3,3,3-trifluoropropylphosphonate were synthesized investigate influence trifluoromethyl substituent on N-terminal coupling.

The manuscript describes concise, practical synthetic approaches toward multigram preparation of value-added conformationally constrained 5-spirocyclic α-prolines from readily accessible starting materials. Direct carboxylation 2-spiropyrrolidines was found to be a...

This work was conducted to study the chemical composition, antioxidant, antibacterial, and antifungal activities of essential oil hydrolat from Withania frutescens. The extracted by hydrodistillation. characterization performed using gas chromatography-mass spectrometry (GC/MS). antioxidant activity studied four different assays (DPPH, TAC, FRAP, β-carotene bleaching). antibacterial test carried out on multidrug-resistant bacteria including Gram-negative Gram-positive strains. Antifungal...

The salt (η5-pentamethylcyclopentadienyl)silicon(II) tetrakis(pentafluorophenyl)borate (5) reacts at −78 °C with lithium bis(trimethylsilyl)amide in dimethoxyethane (DME) as solvent to give quantitatively the compound [bis(trimethylsilyl)amino][pentamethylcyclopentadienyl]silicon(II) 6A form of a colorless viscous oil. reaction performed −40 leads silicon(IV) 7, formal oxidative addition product DME. Cycloaddition is observed 2,3-dimethylbutadiene 8. Upon attempts crystallize from organic...

Accurate full dimensional quantum dynamics calculations studying the photodissociation of CH3I@resorc[4]arene on an ab initio based potential energy surface (PES) model are reported. The converged 189D facilitated by multilayer multi-configurational time-dependent Hartree (ML-MCTDH) approach combined with correlation discrete variable representation (CDVR) for evaluation matrix elements. employed combines established PES describing methyl iodide in A band a harmonic description...

A comprehensive study on the synthesis of 5-fluoroalkyl-substituted isoxazoles starting from functionalized halogenoximes is reported. One-pot metal-free [3 + 2] cycloaddition CF

An electronic spectator in stable carbenes: A weak π-donor substituent such as a phosphanyl group brings enough stabilization to singlet phosphanyl(mesityl)carbenes prepared by photolysis of diazo precursors that the mesityl remains an spectator. The carbenes are sufficiently allow characterization phosphanyl(tert-butyl)- and even phosphanyl(methyl)carbenes (see picture) NMR spectroscopy (mesityl=2,4,6-trimethylphenyl).

The concept of through-space versus through-bond interactions on the stabilization biradical structures with a singlet or triplet ground state is evaluated for 1,3-diboracyclobutane-1,3-diyls and related congeners. Singlet biradicals are favored when intermediate units E feature character (PH(2) (+), AsH(2) (+)), while fragments (NH(2) (+)) induce small energy separations between lowest states. These considerations supported by quantum chemical calculations optimization at 1) MCSCF level...

The formation of a Fischer-type transition metal complex with W(CO)5 fragment is evaluated for the phosphanylcarbenes, Arduengo-type carbenes, and Bertrand-type carbenes by means quantum chemical investigations at density functional level effective core potential methods. Accordingly, stabilities complexes depend strongly on substitution pattern carbenic unit. Amino-substituted as well carbene form stable complexes. decrease phosphanylcarbenes are minimum hitherto unknown push−pull-type...

Based on nanoporous carbon electrodes electrochemical double layer capacitors (EDLC), otherwise known as supercapacitors or ultracapacitors, are currently widely used in various energy storage technologies, wherein the EDLC low internal resistance and long cycle life at an advantage. It is still a good challenge to further reduce of since this can result higher power density efficiency these promising supply units. In work it has been found that depends strongly electrolyte diffusion...

A series of novel spirocyclic α-proline building blocks for drug discovery with a spiro conjunction in position 3 pyrrolidine was prepared by means two convenient and practical synthetic approaches. Both alternative routes utilize simple easily available starting materials – cyclic ketones esters comprise 6- 7-steps, respectively. The methodologies feature several advantages, including exploitation organic chemistry transformations suitability preparation multigram amounts the target...

Parallel Minisci reactions of non-fluorinated and gem-difluorinated C4–C7 cycloalkyl building blocks (trifluoroborates carboxylic acids) with a series electron-deficient heterocycles were studied. A comparison the reaction’s outcome revealed better product yields in case acids as radical precursors most cases, albeit these reagents used three-fold excess under optimized conditions. The nature heterocyclic core was found to be important for successful incorporation fragment. impact CF2 moiety...

A broad range of (phosphino)(aryl)carbenes, 1b−d, 10a,b, and 14a,b, were prepared by photolysis their diazo precursors. The influence the steric electronic properties aryl ring on structure stability these carbenes was studied both experimentally theoretically. Among different stabilization modes investigated, those featuring an acceptor as well a spectator substituent result in stable or at least persistent that could be completely characterized classical spectroscopic methods. In marked...

Recently a new type of calix[4]arenes has been synthesized via condensation 2,6-dihydroxypyridine and number aldehydes. This pyridine[4]arenes forms capsules consisting two single pyridine[4]arenes. These can incorporate different guest molecules, like carboxylic acids amides in this case. We proved that the really are incorporated inside cavity by electrospray mass spectrometry, NMR spectroscopy, theoretical calculations.

Anopheles darlingi is the main vector of malaria in Brazil, characterized by a high level anthropophilia and endophagy. Imidacloprid, thiacloprid, acetamiprid are most widespread insecticides neonicotinoid group. However, they produce adverse effects on non-target insects. Flupyradifurone has been marketed as an alternative to non-fluorinated neonicotinoids. Neonicotinoids containing trifluoroacethyl substituent reveal increased insecticidal activity due higher hydrophobicity metabolic...

A Cu-catalyzed, easily scalable one-pot synthesis of fused pyridines by the reaction cyclic ketones with propargylamine is described. The protocol was optimized based on results more than 30 experiments. highest product yields were achieved in i-PrOH as a solvent presence 5.0 mol % CuCl2 air. In contrast to well-known Au-catalyzed protocol, our procedure "laboratory friendly", cost-effective, and suitable for preparing dozens grams pyridine-based building blocks does not require...

Nickel(II) complexes of Schiff's bases derived from (S)-o-[(N-benzyl]prolyl)amino]benzophenone [N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide] (BBP) and glycine or alanine have been used for asymmetric synthesis fluoro (S)-phenylalanines (S)-α-methyl(phenyl)alanines. Large selectivity (> 90%) is observed the alkylation both 1a 1b. The optically pure phenylalanines are obtained after alkylated diastereoisomeric had separated on silica gel hydrolyzed with aqueous hydrogen chloride.

The effect of cyclochirality rccc-2,8,14,20-tetra-n-decyl-4,10,16,22-tetra-O-methylresorcin[4]arene (C) on the enantiodiscrimination a number chiral bidentate and tridentate aromatic aliphatic biomolecules (G) has been investigated by nano-electrospray ionization (nano-ESI)-Fourier transform ion cyclotron resonance mass spectrometry. experimental approach is based formation diastereomeric proton-bound [C·H·G](+) complexes nano-ESI solutions containing an equimolar amount quasi-enantiomers...

The reaction of trimethyl(trifluoromethyl)silane–tetrabutylammonium difluorotriphenylsilicate (CF3SiMe3–TBAT) with a series imidazoles gives products the formal difluorocarbene insertion into C–H bond at C-2 position (i.e., C-difluoromethylation). According to NMR spectra, corresponding 2-(trimethylsilyl)difluoromethyl-substituted derivatives are likely formed as intermediates in reaction, and then, they slowly convert 2-difluoromethyl-substituted imidazoles. Quantum chemical calculations...

Structural restriction of the sulfonamide bond was used to design sultams with abnormal geometric parameters. Based on analysis tertiary aliphatic sulfonamides published in Cambridge crystallographic database, Paquette's (i.e., bridged bicyclic a bridgehead nitrogen atom) were outlined, and number these compounds (including novel smallest representative, 2-thia-1-azabicyclo[2.1.1]hexane 2,2-dioxide) synthesized by cyclization corresponding amino sulfonyl fluorides. A series studied quantum...