N-methylated 25-oxasmaragdyrins: Synthesis, structure and properties

2016 ◽  
Vol 20 (05) ◽  
pp. 582-589
Author(s):  
Tejinder Kaur ◽  
Way-Zen Lee ◽  
Mangalampalli Ravikanth
Keyword(s):  
Pyrrole Ring ◽  
Electrochemical Techniques ◽  
Soret Band ◽  
2D Nmr ◽  
Structure And Properties ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Structural And Electronic Properties

The [Formula: see text]-methylated 25-oxasmaragdyrins were synthesized by reacting 25-oxasmaragdyrins with CH3I in presence of KOH in THF at reflux temperature. Although the reactions were carried out in presence of excess CH3I, we obtained only dimethyl-25-oxasma ragdyrins, where [Formula: see text]-methylations occurred at 24 and 26 “N”s of pyrrole rings of tripyrrane moiety of smaragdyrin core as confirmed by X-ray crystallography. The [Formula: see text]-methylated-25-oxasmaragdyrins were characterized in detail by 1D and 2D NMR spectroscopy, absorption, fluorescence and electrochemical techniques. The effect of distortion induced by methylation, clearly reflected in structural and electronic properties of the macrocycle. All the pyrrole and furan protons experienced upfield shifts in the 1H NMR and maximum upfield shifts were noted for the [Formula: see text]-methylated pyrrole ring protons. The absorption spectra showed broad Soret band and four ill-defined Q-bands with significant reduction in extinction coefficients. The [Formula: see text]-methylated 25-oxasmaragdyrins were comparatively less fluorescent. The redox studies indicated that they are difficult to oxidize and easier to reduce.

One-pot synthesis of 5-(8-ethoxycarbonyl-1-naphthyl)-10,15,20-triphenyl porphyrin (ENTPP) and spontaneous resolution upon crystallization

2011 ◽  
Vol 15 (03) ◽  
pp. 197-201 ◽  
Author(s):  
Juanxia Yang ◽  
Jiaxun Jiang ◽  
Weiguang Fang ◽  
Xiaoxu Kai ◽  
Chuanjiang Hu ◽  
...  
Keyword(s):  
Soret Band ◽  
Ester Group ◽  
Spontaneous Resolution ◽  
Cd Spectra ◽  
One Pot ◽  
Nmr Spectrum ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Entire Structure

5-(8-ethoxycarbonyl-1-naphthyl)-10,15,20-triphenyl porphyrin (ENTPP) has been synthesized in a one-pot reaction, and the corresponding chiral crystalline samples have been obtained by spontaneous resolution. 1 H NMR spectrum suggests it is mononaphthyl substituted species and an ethyl group is over the porphyrin plane. The structure has been further confirmed by X-ray crystallography. ENTPP·C6H14 (C57H50N4O2 ): monoclinic, P21, a = 10.707(2) Å, b = 12.203(2) Å, c = 17.858(4) Å, β = 103.06(3)°, V = 2272.8(8) Å3, Z = 2. The 8-position substituent, ester group, lies above the porphyrin plane and leads to the conformational chirality. The entire structure is built up with homochiral molecules, which leads to a chiral crystal through packing in P21 space group. Circular dichroism (CD) spectra have exhibited remarkable absorptions in the Soret band region, which further confirms the homochirality of the crystalline samples.

New polysubstituted monoterpenic thiazolidinones: synthesis, spectroscopic and crystal structure studies

2018 ◽  
Vol 74 (12) ◽  
pp. 1629-1634 ◽  
Author(s):  
Abdellah N'ait Ousidi ◽  
Moulay Youssef Ait Itto ◽  
Aziz Auhmani ◽  
Abdelkhalek Riahi ◽  
Anthony Robert ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Asymmetric Unit ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography ◽  
Naturally Occurring ◽  
Spectroscopic Analyses ◽  
Graph Set

The synthesis of three new polysubstituted monoterpenic thiazolidin-4-ones, namely (Z)-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C14H21N3OS (2), (2Z,5Z)-5-[(dimethylamino)methylidene]-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C16H24N4OS (3), and (2Z,5Z)-5-[(dimethylamino)methylidene]-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C17H26N4OS (4), is reported, starting from the corresponding thiosemicarbazones obtained from naturally occurring (R)-camphor. All the newly obtained thiazolidin-4-ones have been fully characterized by HRMS and 1H and 13C (1D and 2D) NMR spectroscopy. Two of them, i.e. 2 and 3, were identified by single-crystal X-ray crystallography, confirming the synthetic pathway and the spectroscopic analyses. In 3, there are two roughly identical molecules within the asymmetric unit with the same absolute configuration. These two molecules are linked through N—H...O hydrogen bonds, building an R 2 2(8) graph-set motif.

Epikatonic acid fromAustroplenckia populnea: structure elucidation by 2D NMR spectroscopy and X-ray crystallography

2002 ◽  
Vol 40 (5) ◽  
pp. 366-370 ◽  
Author(s):  
G. D. F. Silva ◽  
L. P. Duarte ◽  
S. A. Vieira Filho ◽  
A. C. Doriguetto ◽  
Y. P. Mascarenhas ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structure Elucidation ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Synthesis and Insecticidal Activities of Novel Derivatives of 1β,4α,6α,9α-Tetrahydroxy-2β,12-epoxymethano-β-dihydroagarofuran

2013 ◽  
Vol 8 (6) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Jiwen Zhang ◽  
Zhan Hu ◽  
Shengkun Li ◽  
Shuding Yang ◽  
Wenjun Wu
Keyword(s):  
2D Nmr ◽  
Root Bark ◽  
Mythimna Separata ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Important Intermediate ◽  
Derivatives Of ◽  
C Nmr ◽  
Insecticidal Activities

In order to develop novel biorational pesticides, twelve new ether derivatives of 1β,4α,6α,9α-tetrahydroxy-2β,12-epoxymethano-β-dihydroagarofuran (3) were synthesized. The structure of the important intermediate 3 was confirmed by X-ray crystallography, and the new derivatives (3.1–3.12) were elucidated by IR, 1H NMR, 13 C NMR and 2D NMR spectroscopic and ESI-MS analysis. Insecticidal activities of these derivatives were tested against the third-instar larvae of Mythimna separata. Though most of the derivatives (3.1–3.4, 3.6, 3.8, 3.9–3.12) revealed no obvious activities at the concentration of 10 mg/mL –1, two compounds 3.5 and 3.7, with KD50 values of 12.9 (μg/g-1 and 7.8 μg/g –1, respectively, showed much higher insecticidal activities than celangulin-V, with a KD50 of 321.4 μg·g–1, the main insecticidal component from the root bark of Chinese bittersweet, Celastrus angulatus Max. The results showed that β-dihydroagarofuran has the potential to be a lead structure for semi-synthetic green insecticides.

Guyanin, a novel tetranortriterpenoid: structural characterization by 2D NMR spectroscopy and x-ray crystallography

1988 ◽  
Vol 110 (16) ◽  
pp. 5339-5344 ◽  
Author(s):  
Stewart. McLean ◽  
Marion. Perpick-Dumont ◽  
William F. Reynolds ◽  
Jeffery F. Sawyer ◽  
Helen. Jacobs ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Characterization ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography

ChemInform Abstract: Guyanin, a Novel Tetranortriterpenoid: Structural Characterization by 2D NMR Spectroscopy and X-Ray Crystallography.

ChemInform ◽  
1988 ◽  
Vol 19 (47) ◽  
Author(s):  
S. MCLEAN ◽  
M. PERPICK-DUMONT ◽  
W. F. REYNOLDS ◽  
J. F. SAWYER ◽  
H. JACOBS ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Characterization ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography

Supramoleküle aus Kronenethern und geminalen Sulfonen: Synthese von vier binären Komplexen und Kristallstruktur von (CH2CH2O)4·2H 2C(SO2C2H5)2/Supramolecules of Crown Ethers with Geminal Sulfones: Synthesis of Four Binary Complexes and Crystal Structure of (CH2CH2O )4·2H2C(SO2C2H5)2

1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Binary Complexes ◽  
Cyclic Polyethers ◽  
Adjacent Unit ◽  
Methylene Group

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.

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