Zoia Voitenko

Synthesis of 3-heteryl substituted pyrrolidine-2,5-diones via catalytic Michael reaction and evaluation of their inhibitory activity against InhA and Mycobacterium tuberculosis

In the present paper, we report the synthesis via catalytic Michael reaction and biological results of a series of 3-heteryl substituted pyrrolidine-2,5-dione derivatives as moderate inhibitors against Mycobacterium tuberculosis H37Rv growth. Some of them present also inhibition activities against InhA.

Structure of the Cycloaddition Products of Pyrido[2,1-a]isoindole with Maleimide Derivatives: X-ray Diffraction Analysis and1H NMR Variable-Temperature Spectra

Investigation of the cycloaddition reaction under thermodynamic control of pyrido[2,1-a]isoindole with maleimide derivatives revealed a new rearrangement leading to 2-{2′-[(1R)2,5-dioxopyrrolidinylidene]-2′-[(1R)-2,5-dioxopyrrolidinyl)methyl]}phenylpyridine. Their structure was confirmed by X-ray diffraction analysis. The atropisomeric properties of the obtained compounds were examined in a detailed NMR spectroscopic study. Dependence of the spectra on temperature was investigated, and coalescence temperatures and conversion barriers between the corresponding atropisomers determined.

Newly substituted pentamethine merocyanines. Part 1: Synthesis, physical properties, and synthetic applications

Abstract New 1,5-substituted pentamethine merocyanine dyes were synthesised in high yields. Their reaction towards acid chlorides or anhydrides leads to new hemicarboxonium salts with enhanced reactivity due to their better leaving groups. They are able to combine with soft nucleophiles to obtain a new cyanine dyes series. Thus, these merocyanines may be used as stable intermediate reagents in cyanine synthesis. Moreover, from a theoretical point of view, the synthesis of substituted derivatives of the well-known polyenic donor acceptor models for non-linear optics, opens the route to physicochemical determinations of their effects on the polarisation of the chain and the bond length alternation (Part 2 of study in progress).

A self-assembled M2L4 cage incorporating electron-rich 9-(1,3-dithiol-2-ylidene)fluorene units

An electron-rich redox-active M2L4 cage is depicted. The cage is constructed through coordination driven self-assembly of a 9-(1,3-dithiol-2-ylidene)fluorene bis-pyridyl ligand in the presence of the Pd(BF4)2(CH3CN)4 complex. The corresponding discrete structure has been fully characterized in the solution as well in the solid state (crystal structure), showing notably that each of the four ligands surrounding the cavity can be reversibly oxidized upon a one electron process.

Catalysis by Lithium Perchlorate Enables Double-Conjugate Addition of Electron-Deficient Maleimides to 2-Aminopyridines and 2-Aminothiazoles

Abstract Lithium perchlorate has been found to catalyze the conjugate addition of maleimides with 2-aminopyridines and 2-aminothiazoles. The reaction proceeds under mild conditions leading to the corresponding double adducts in good yields. A plausible mechanism of this reaction has been proposed. Supplemental materials are available for this article. Go to the publishers online edition of Synthetic Communications ® to view the free supplemental file. GRAPHICAL ABSTRACT

Synthesis and stereochemical configuration of inherently chiral p-tert-butylcalix[4]arene carboxylic acids and their derivatives

Both enantiomers of inherently chiral p-tert-butylcalix[4]arene carboxylic acids with ABHH substitution patterns have been prepared by stereoselective reaction of monopropoxy-p-tert-butylcalix[4]arene with an (R)-N-(1-phenylethyl)bromoacetamide, separation of the diastereomers by column chromatography, and removal of the chiral auxiliary groups. The absolute configuration of obtained compounds has been established by X-ray analysis.Graphical Abstract

2-Substituted-isoindoles: a novel synthetic route and a study of the Diels–Alder and Michael reactions

A novel one-step procedure for the synthesis of 2-substituted-isoindoles and 1-aryl-2-substituted-isoindoles is described. The procedure is based on the reaction of 2-(bromomethyl)benzaldehyde or 2-(bromomethyl)benzophen-one derivatives with primary aromatic or aliphatic amines. Reactions of 1,2-diarylisoindoles with N-phenylmaleimide were studied. Refluxing the reactants in i-PrOH in the presence of triethylamine leads to the formation of Diels–Alder endo-adducts; whilst refluxing in AcOH in the presence of AcONa affords Michael adducts. The structure of the latter was confirmed by X-ray diffraction.

Synthesis of an Enantiomerically Pure Inherently Chiral Calix[4]Arene Phosphonic Acid and Its Evaluation as an Organocatalyst

A facile method for the preparation of enantiomerically pure inherently chiral calix[4]arene phosphonic acid (cR,pR)-7 in four steps starting from the readily available and previously synthesized (cS)-enantiomer of calix[4]arene acetic acid 1 or its methyl ester 2 was developed. The first tests of this unique calixarene Brönsted acid with inherent chirality in organocatalysis of the aza-Diels-Alder reaction of imines with Danishefskys diene and epoxide ring opening by benzoic acid were performed. The calixarene phosphonic acid (cR,pR)-7 shows good catalytic activities but with low enantioselectivities in these reactions.

Alkyl Triarylstannanecarbodithioates: Synthesis, Crystal Structures and Efficiency in RAFT Polymerization

Eight alkyl triarylstannanecarbodithioates were synthesized starting from the corresponding triarylstannyl chlorides. They were fully characterized by IR and 1 H, 13 C, and 119 Sn NMR spectroscopy and mass spectrometry. Their solid-state structures and geometric parameters were determined and compared to those of other classes of thiocarbonylthio compounds. These new organotin derivatives are efficient reversible chain-transfer agents for reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St) and n-butyl acrylate (BA), with controlled number-average molecular weights and narrow dispersities (Ð<1.3). In some cases, loss of control of the polymerization was evidenced and supported by the observation of side products by 119 Sn NMR spectroscopy. This phenomenon was attributed to the thermal instability of the Sn-RAFT terminal group.

Methyl N-(3-cyano-picolino-yl)-l-tryptophanate.

In the title compound, C19H16N4O3, the stereocenter has an l configuration; l-tryptophan methyl ester hydrochloride being used as a starting material. The indole ring system and the pyridine ring are inclined to one another by 13.55 (14)°. In the crystal, adjacent molecules are linked via N—H⋯O hydrogen bonds, forming chains propagating along the c-axis direction.