Synthesis of novel α-aminoecdysteroids via regio- and stereoselective oximation/hydrogenation of 20-hydroxyecdysone derivatives

2017 ◽  
Vol 95 (2) ◽  
pp. 130-133 ◽  
Author(s):  
Rimma G. Savchenko ◽  
Svetlana A. Kostyleva ◽  
Ekaterina S. Meshcheryakova ◽  
Leonard M. Khalilov ◽  
Lyudmila V. Parfenova ◽  
...  

Oximation of 20-hydroxyecdysone oxo derivatives proceeds regio- and stereoselectively and provides (E)-configured oximes in quantitative yields. The Ni–Ra-catalyzed hydrogenation of the oximes affords novel α-aminoecdysteroids with the unchanged 14α-hydroxy-7-en-6-on native chromophore of ecdysteroids. The structures of synthesized compounds were confirmed by the means of homo- and heteronuclear one-dimensional and two-dimensional 1H and 13C NMR spectroscopy and X-ray crystallography.

2020 ◽  
Vol 75 (4) ◽  
pp. 341-345
Author(s):  
Xiao-Li Liu ◽  
Jing-Long Liu ◽  
Hong-Mei Yang ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang

AbstractCo-crystallization of C-propyl-pyrogallol[4]arene (PgC3) with 4,4′-bipyridine (bpy) in ethanol afforded a multi-component complex (PgC3) · 3(bpy) ·(EtOH) (1) that consists of a one-dimensional brick-wall framework, which was formed by four pyrogallol[4]arene molecules and two juxtaposed bpy molecules, entrapping two other bpy molecules as guests within each cavity. Heating a mixture of PgC3 and trans-1,2-bis-(4-pyridyl)ethylene (bpe) in an ethanol-water mixed solvent allowed the isolation of a multi-component complex (PgC3) ·(bpe) · 2(EtOH) ·(H2O) (2), which has a two-dimensional wave-like polymer structure with the bpe molecules embedded in the wave trough between two PgC3 molecules. Single-crystal X-ray crystallography was utilized to investigate the hydrogen bonding networks of the multi-component complexes 1 and 2.


2005 ◽  
Vol 60 (10) ◽  
pp. 1049-1053 ◽  
Author(s):  
Zeanab Talaei ◽  
Ali Morsali ◽  
Ali R. Mahjoub

Two new ZnII(phen)2 complexes with trichloroacetate and acetate anions, [Zn(phen)2(CCl3COO)- (H2O)](ClO4) and [Zn(phen)2(CH3COO)](ClO4), have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. The single crystal X-ray data of these compounds show the Zn atoms to have six-coordinate geometry. From IR spectra and X-ray crystallography it is established that the coordination of the COO− group is different for trichloroacetate and acetate. The former acts as a monodentate whereas the latter acts as a bidentate ligand.


2018 ◽  
Vol 273 ◽  
pp. 134-139
Author(s):  
M.A. Kadir ◽  
Christopher J. Sumby

Reaction of diamide ligand, namelyN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide (L) with cadmium nitrate and cadmium perchlorate has given rise to the formation of two types coordination polymers. Compound (CP1-Cd) with formula molecule {[Cd (L)2(H2O)2](NO3)2·6H2O}nis a one-dimensional coordination polymer while compound (CP2-Cd), with formula molecule {[Cd (L)2(H2O)2](ClO4)2·31⁄2H2O.CH3OH}n, is a two dimensional coordination polymer. These coordination polymers were preparedviaslow evaporation methods and completely characterized by combination of solid state techniques such as Fourier Transform Infrared (FTIR) spectroscopy, elemental analysis and X-ray crystallography. This study revealed that coordination polymers derived fromN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide can accommodate anions with different sizes, showing good potential as anion receptor.


1998 ◽  
Vol 76 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Donald L Hooper ◽  
Ian R Pottie ◽  
Marc Vacheresse ◽  
Keith Vaughan

A series of novel bistriazenes, the 1,2-bis(1-aryl-3-methyltriazen-3-yl)ethanes, Ar-N T N-NMe-CH2CH2-NMe-N T N-Ar, have been synthesized by diazonium coupling with N,N'-dimethylethylenediamine. These bistriazenes are stable crystalline compounds and have been unequivocally characterized by IR and NMR spectroscopy (1H and 13C), and elemental analysis. The structures of two compounds in the series have been confirmed by X-ray crystallography. The 1H NMR spectra show significant line broadening of the N-methyl resonances arising from the restricted rotation around the N2-N3 bond of the triazene units. The presence of strongly electron-withdrawing groups on the aryl ring restricts the rotation to the point where the N-methyl signals of the rotamers are distinct even at room temperature; four resonances of the N-methyl signal are clearly evident and these can be assigned to the anti-anti, syn-syn, and syn-anti conformations of the bistriazene. Diazonium coupling with N,N'-diethylethylenediamine affords the N,N'-diethyl homologues of the bistriazenes, which have been similarly characterized. As model compounds to assist in spectroscopic analysis, a series of related triazenes, the 1-(1-aryl-3-methyltriazen-3-yl)-N,N-dimethyl-2-ethanamines, were prepared by diazonium coupling with N,N,N'-trimethylethylenediamine. These dialkyltriazenes exist mainly as oils, but characterization was achieved by IR, 1H NMR, and 13C NMR spectroscopy, also showing the presence of two rotamers in solution when strongly electron-withdrawing substituents are bonded to the aryl moiety.Key words: triazene, bistriazene, diazonium, ethylenediamine, molecular dynamics, NMR.


2010 ◽  
Vol 65 (2) ◽  
pp. 128-134 ◽  
Author(s):  
Farzin Marandi ◽  
Zahra Nikpey ◽  
Jia Hao Goh ◽  
Hoong-Kun Fun

Three substituted 2,2'-bipyridine adducts of lead(II) thenoyltrifluoroacetonate, [Pb(4,4'-dm-2,2’- bpy)(ttfa)2]2, 1, [Pb(5,5' -dm-2,2’-bpy)(ttfa)2]2, 2, and [Pb(4,4'-dmo-2,2’-bpy)(ttfa)2], 3, (4,4’ -dm- 2,2’-bpy, 5,5’-dm-2,2’-bpy, 4,4’-dmo-2,2’-bpy and ttfa are the abbreviations for 4,4’-dimethyl-, 5,5’-dimethyl-, and 4,4’-dimethoxy-2,2’-bipyridine, and thenoyltrifluoroacetonate, respectively) have been synthesized, characterized by elemental and thermal analysis, IR and 1H- and 13C-NMR spectroscopy, and studied by X-ray crystallography. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions.


2013 ◽  
Vol 101 (10) ◽  
pp. 631-636 ◽  
Author(s):  
A. L. Tamasi ◽  
C. L. Barnes ◽  
J. R. Walensky

Summary The synthesis of uranyl complexes coordinated to tridentate, monoanionic salicylaldiminate (Schiff base) ligands was achieved by the reaction of UO2Cl2(THF)3, 1, with one equivalent of the corresponding sodium salicylaldiminate salts affording [(C9H6N)N=C(H)C6H2t Bu2O]UO2Cl(THF), 2, [(NC5H4)N=C(H)C6H2 t Bu2O]UO2Cl(THF), 3, and [(C6H4SCH3)N=C(H)C6H2tBu2O]UO2Cl(THF), 4. These are uncommon examples of uranyl complexes with a monoanionic ancillary ligand to stabilize the coordination sphere and one chloride ligand. Compounds 2-4 have been characterized by 1H and 13C NMR spectroscopy as well as IR and UVVis spectroscopy and their structures determined by X-ray crystallography.


Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 513 ◽  
Author(s):  
Santana A.L. Thomas ◽  
Anthony Sanchez ◽  
Younghoon Kee ◽  
Nerida G. Wilson ◽  
Bill J. Baker

An Antarctic coral belonging to the order Pennatulacea, collected during the 2013 austral autumn by trawl from 662 to 944 m depth, has yielded three new briarane diterpenes, bathyptilone A-C (1–3) along with a trinorditerpene, enbepeanone A (4), which bears a new carbon skeleton. Structure elucidation was facilitated by one- and two-dimensional NMR spectroscopy, mass spectrometry and confirmed by X-ray crystallography. The three compounds were screened in four cancer cell lines. Bathyptilone A displayed selective nanomolar cytotoxicity against the neurogenic mammalian cell line Ntera-2.


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