Synthesis of new mono and bis amides projected as potential histone deacetylase (HDAC) inhibitors

In our ongoing efforts to discover new potent histone deacetylase (HDAC) inhibitors as promising anticancer candidates, we designed and synthesized a small collection of 3-substituted amines possessing macro heterocyclic skeletons bearing variable-length tails. As a metal binder domain, all the compounds possess an amide function suitable for Zn²⁺ chelation in the enzyme active site. A combination of solution and solid phase techniques were employed to synthesize the compounds and, as the key synthetic step to obtain the rings, a ring closing metathesis (RCM) reaction was adopted. The putative affinity of the compounds for the histone deacetylase-like protein (HDLP) model receptor active site was explored through docking calculations, and we also report preliminary studies on their pharmacological properties.     

Synthesis, complexation studies and biological activity of some novel mono and tricyclic cyclophane amides and cyclophane sulfonamides

A series of mono, tricyclic cyclophane tetraamides and cyclophane sulfonamides have been synthesized and characterized from spectral and XRD studies. All the cyclophane amides form charge transfer (CT) complex with TCNQ. The cyclophane amides show moderate to good anti-inflammatory activity. Some of them were active against Gram positive (Klebsiella pneumonia) and Gram negative (Escherichia coli and Staphylococcus aureus) human pathogens.     

Synthesis, characterization and ion transportation studies of some novel cyclophane amides

Various novel cyclophane amides with a large cavity have been synthesized. The structures of cyclophane amides 14 and 15 were resolved using XRD studies. Cyclophane amide 28 shows a shift in λ_max in the UV/Vis. spectra when treated with Cu (II) ion as well as with Pb (II) ion. Ion transportation studies were carried out with cyclophane amide 14 which proved that the Na⁺ ion passes through the cavity while K⁺ ions are retained.     

Synthesis, characterization and complexation studies of some novel cyclophane amides and sulfonamides

A series of tricyclic tetraamides have been synthesized and were characterized from spectral and XRD studies. XRD studies revealed that the pyridine-based tricyclic cyclophane amide exists with twisted phenyl rings. All the cyclophane compounds form charge-transfer (CT) complexes with TCNQ. Metal ion complexation studies show that the cyclophane amides are more selective towards Cu(II) ions rather than Ni(II) and Cd(II) ions.     

Synthesis, characterization, and ethylene polymerizations of various N-O chelated mono Cp titanium complexes

Various mono Cp^∗ type titanium mononuclear complexes (1-5) and dinuclear complexes (6 and 7) containing non-Cp type chelate ligand, picolinate group, which has multi-binding sites of N and O atoms were synthesized and fully characterized by ¹H and ¹³C NMR spectroscopy, mass spectroscopy, elemental analysis, and X-ray diffraction study. The 1 and 2/MMAO catalytic systems for ethylene polymerization exhibited a moderate activity and gave the polyethylenes with broad molecular weight distributions.     

Synthesis,structural, and spectral characterization of Keggin-type mono cobalt(II)-substituted phosphotungstate

Keggin-type mono Co(II)-substituted phosphotungstate was synthesized from 12-tungstophosphoric acid and cobalt chloride tetrahydrate. The obtained complex was systematically characterized in solution as well as solid by various physicochemical techniques. A single-crystal X-ray analysis shows that the complex crystallizes in tetragonal system, P4₂/ncm space group with a?=?b?=?20.9860(5)?Å, c?=?10.4368(3)?Å, and Z?=?4. The crystal showed two types of disorders related by center of symmetry. Structural studies did not show the presence of Co, but the incorporation of the metal ion was proved by various spectral techniques. Spectral as well as electrochemical studies confirmed the presence of Co(II) into the lacunary position of the phosphotungstate moiety.     

Synthesis of n-vinyloxyethylated amides and ureas

Conclusions N-Vinyloxyethylated amides were synthesized by reacting the vinyl ethers of amino and ketimino alcohols with the acid chlorides of the 2,4-dichlorophenoxyacetic, o-, and p- chlorobenzoic acids, while the previously unknown N-vinyloxyethylated derivatives of ureas were obtained from the vinyl ethers of amino alcohols and aryl isocyanates.Translated fron Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1893–1896, August, 1981.     

Synthesis and properties of phenylogous amides

Vinylogy is a widely accepted principle involving the transfer of electronic chemical character through a double bond, and many reactions have been developed by applying this concept. In contrast, phenylogy, which involves the connection of two substituents through a benzene ring, is rarely recognized as a related idea. In this article, we present synthesis and physical properties, including their structure and reactivity of phenylogous amides. This amide mimetic unit is relatively stable and easily prepared by the Hartwig–Buchwald amination reaction. The effect of the resonance was examined by means of crystallography, reactivity and UV–vis spectroscopy.     

Chemistry of alkoxo complexes,part II. Synthesis and characterization of some mono(chelato)mono(alkoxo)nickel(II) complexes

Summary Mono(chelato)mono(alkoxo)nickel(II) complexes of the general formula, Ni(OR)(dk) (R = Me, i-Pr and dk = acac, bazac, dbzm and tta) have been synthesized by the reactions of nickel alkoxides, Ni(OR)₂(R = Me and i-Pr) with acetylacetone (Hacac), benzoylacetone (Hbzac), dibenzoylmethane (Hdbzm) and 2-thienoyltrifluoroacetone (Htta). These derivatives interchange their alkoxy groups quantitatively with other alcohols. Molecular weight, i.r., electron spin resonance, electronic reflectance spectral and magnetic susceptibility studies have been carried out.Part. 1.Transition Met. Chem.,2, 204 (1977)     

Synthesis of nitroxylcarbamidophosphoric acid amides

A method for obtaining new organophosphorus nitroxyls was developed based on Kirsanov's phosphazo reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1139–1141, May, 1990.     

Reaction of zirconium hydrocarbyls with carbon monoxide

Carbon monoxide reacts with tetrahydrocarbylzirconium compounds, (RCH₂)₄Zr, where R = phenyl or vinyl to give a polymeric species containing ZrOC bonds, which on hydrolysis yields products consistent with successive insertion of CO and ZrC(O)CH₂R into the ZrC bonds.     

Synthesis of thiophosphoric acid amides

Conclusions The cyclohexylamido- and piperididothiophosphoric acids were obtained for the first time, and also piperazido-N,N-bisthiophosphoric acid as the Na and NH₄ salts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2402–2403, October, 1982.     

Synthesis of betulonic acid amides

Betulonic acid amides of interest as potential biologically active compounds were prepared. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 259–264, May–June, 2008.     

Synthesis of enamides from aldehydes and amides

A range of double unsaturated amides (15, 19, and 21), obtained by cross-coupling reactions was reacted with aldehydes to hemiaminals. Heating the hemiaminals in the presence of Ac₂O and pyridine affected clean conversion to the corresponding enamides, such as 42, 45, and 47. Alternatively, N,S-acetals were prepared which were oxidized to the sulfones. Treatment with base also gave the enamides, favoring the cis-isomer. However, this method is less general. Application of these methods led to the natural products lansiumamide-A (30_cis), lansiumamide-I (31) and lansiumamide-B (32).     

Synthesis, characterization, and reaction of aluminum halide amides supported by a bulky beta-diketiminato ligand

Monomeric aluminum chloride amides with the general formula LAl(Cl)NR2 (1, R = Me; 2, R = iPr; 3, R = SiMe 3; L = HC[C(Me)N(Ar)]2; Ar = 2,6- iPr2C6H3) were prepared by selected routes. Treatment of LAlBr 2 (4) and LAlI2 with LiNMe2 yielded LAl(Br)NMe2 (5) and LAl(I)NMe2 (6), respectively. The alkylation of 1 and 2 with MeLi gave the corresponding methylated compounds LAl(Me)NR2 (7, R = Me; 8, R = iPr); however, no reaction of 3 with MeLi was observed because of steric hindrance. Subsequent fluorination of 1- 3 afforded LAl(F)NR2 (9, R = Me; 10, R = iPr; 11, R = SiMe3). Compounds 1-11 were characterized by multinuclear NMR, electron impact mass spectrometry, and IR. The constitution of compounds 1-3 was confirmed by single-crystal X-ray diffraction studies.     

Synthesis and characterization of chiral mono N-heterocyclic carbene-substituted rhodium complexes and their catalytic properties in hydrosilylation reactions

Different chiral mono-substituted N-heterocyclic carbene complexes of rhodium were prepared, starting from [Rh(COD)Cl]₂ (COD = cyclooctadiene) by addition of free N-heterocyclic carbenes (NHC), or an in-situ deprotonation of the corresponding iminium salt. All new complexes were characterized by spectroscopy methods. In addition, the structures of chloro(η⁴-1,5-cyclooctadiene)(1,3-di-[(1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl] imidazolin-2-ylidene)rhodium(I) (5a), chloro(η⁴-1,5-cyclooctadiene)(1,3-di-[(1R,2S,5R)-2-isopropyl-5-menthylcyclohex-1-yl]imidazol-2-ylidene)rhodium(I) (5b) and chloro(η⁴-1,5-cyclooctadiene)(1,3-di-[(2R,4S,5S)-2-methyl-4-phenyl-1,3-dioxacyclohex-5-yl]imidazolin-2-ylidene)rhodium(I) (5i) were analyzed by DFT-calculations. The enantioselective hydrosilylation of acetophenone, ethylpyruvate and n-propylpyruvate with diphenylsilane and hydrolysis was carried out with chiral C₂-symmetrical mono-substituted N-heterocyclic carbene rhodium complexes giving for the first time an enantioselective excess of up to 74% ee in the case of the n-propylpyruvate.     

Synthesis of mono N-trifluoroethylated cyclic dipeptides

Trifluoroethylated N-termini in linear dipeptides l-TyrXOR [X = Gly, d-Ala, l-Leu, l-Phe, and l-Glu; R = H, Me, Et] exhibit sufficient nucleophilicity to give piperazine-2,5-dione ring formation through intramolecular cyclization reaction in acidic aqueous solutions. The reactions occur in high yield and with absolute configuration retention.