Novel Synthesis and Structure of a Bridging Peroxo Pentaaminecobalt(III) Dimer

1986 ◽  
Vol 39 (9) ◽  
pp. 1331 ◽  
Author(s):  
GJ Gainsford ◽  
WG Jackson ◽  
AM Sargeson
Keyword(s):  
Single Crystal ◽  
Ethyl Ester ◽  
Dimer Formation ◽  
X Ray ◽  
Mild Conditions ◽  
Novel Synthesis ◽  
Glycine Ethyl Ester ◽  
Perchlorate Salt

The addition of excess glycine ethyl ester to Co{(H2NCH2CH2)3N}(OSMe2)23+ in Me2SO leads to the symmetrical dimeric peroxo ion p,p - [Co( tren )(NH2CH2CO2Et)]2O24+ under mild conditions. The single-crystal X- ray structure of the perchlorate salt is described, and the mechanism for the dimer formation is considered.

scholarly journals Novel synthesis of furancarboxylate derivatives via cyclization reactions of (E)-ethyl 3-aryl-2-cyanoacrylates and ethyl glycinate hydrochloride

2020 ◽  
pp. 174751982095959
Author(s):  
Naili Luo ◽  
Shan Wang ◽  
Zhenjie Su ◽  
Cunde Wang
Keyword(s):  
Synthetic Approach ◽  
Cyclization Reactions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Novel Synthesis ◽  
Substituted Furans

An efficient synthetic approach for the preparation of densely substituted furans starting from ( E)-ethyl 3-aryl-2-cyanoacrylates and ethyl glycinate hydrochloride mediated by 1,8-diazabicyclo[5.4.0]undec-7-ene in the presence of water is investigated. The reactions are carried out under mild conditions in N,N-dimethylformamide at 95 °C. The products are cleanly obtained in 50%–57% yields, resulting in an appealing alternative for accessing polysubstituted furan-2,4-dicarboxylates. The structure of a typical product, diethyl 5-amino-3-( p-tolyl)furan-2,4-dicarboxylate, is confirmed by X-ray crystallography.

The Stereoisomers of 5-Bromo-6,8-dimethoxy-1,2,3-trimethyl-1,2,3,4-tetrahydroisoquinoline. X-Ray Crystal-Structure of the trans Isomer

1990 ◽  
Vol 43 (1) ◽  
pp. 79 ◽  
Author(s):  
MA Rizzacasa ◽  
MV Sargent ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Trans Isomer ◽  
Henry Reaction ◽  
X Ray ◽  
Mild Conditions ◽  
Threo Isomer

Henry reaction between 3,5-dimethoxybenzaldehyde (2) and nitroethane gave (E)-2-(3,5-dimethoxyphenyl)-1-methyl-1-nitroethene (3). Under mild conditions the erythro and threo nitro aldols intermediate in this reaction could be isolated as their acetates. The threo isomer was obtained in diastereoisomeric excess. The nitrostyrene (3) was converted in several steps into cis-(20) and trans-5-bromo-6,8-dimethoxy-1,2,3-trimethyl-1,2,3,4-tetrahydroisoquinoline (18). The single-crystal X-ray structure of compound (18) is reported.

C-H Amination of Nitro Aza-Heterocyclic Compounds by Vicarious Nucleophilic Substitution

Synlett ◽  
2021 ◽  
Author(s):  
RuShuang Zhou ◽  
Chun Cai
Keyword(s):  
Reaction Mechanism ◽  
Reaction Time ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Heterocyclic Compounds ◽  
X Ray Diffraction ◽  
Short Reaction Time ◽  
X Ray ◽  
Vicarious Nucleophilic Substitution ◽  
Mild Conditions

This manuscript describes the C-H amination of a variety of nitro aza-heterocyclic compounds by Vicarious Nucleophilic Substitution (VNS) methodology with 4-amino-1,2,4-triazole (ATA). The aminated products were characterized by NMR, MS and single-crystal X-ray diffraction. Among the substrates examined, moderate to excellent yield (30-88%) and good regioselectivity (ortho/para position of the nitro) are exhibited. This protocol offers the advantages of mild conditions, short reaction time (only 2-4 h) with inexpensive, commercially available and less toxic amination reagent, no additional catalysts or reagents needed. Possible reaction mechanism was also discussed.

Thiophene ring-opening reactions IV. Facile generation of novel ethyl 4-hydroxy-6-thioxonicotinate─1,3,4- thiadiazoline hybrids

2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammed M. Abadleh ◽  
Ahmad H. Abdullah ◽  
Jalal A. Zahra ◽  
Salim S. Sabri ◽  
Firas F. Awwadi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
1H Nmr ◽  
13C Nmr ◽  
Ring Opening ◽  
Thiophene Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Ring Opening Reactions

: A set of triethylammonium 4-oxo-6-pyridinethiolate–1,3,4-thiadiazoline hybrids (3a-e) were prepared via the reaction of ethyl 2-chloro-6-cyclopropyl-3- nitro-4-oxothieno[2,3-b]pyridine- 5-carboxylate (2) with the appropriate thiobenzoyl- hydrazide (1a-e) in acetonitrile and triethylamine. These hybrids were readily converted, under neutral mild conditions, into the corresponding 4-hydroxy-6-thioxopyridine –thiadiazoline hybrids (5a-e). The structures of the latter set are supported by HRMS, 1H NMR and 13C NMR spectral data and further confirmed by single-crystal X-ray diffraction studies. Alkylation of these hybrids in the presence of triethylamine occurred exclusively at the 6-thioxosulfur, yielding the respective 6-sulfanyl derivatives (6a-c).

Sigmosceptrins A - C: New Norditerpenes from a Southern Australian Marine Sponge, Sigmosceptrella sp.

1997 ◽  
Vol 50 (12) ◽  
pp. 1137 ◽  
Author(s):  
Sean Bassett, ◽  
Simon P. B. Ovenden ◽  
Robert W. Gable ◽  
Robert J. Capon
Keyword(s):  
Structural Analysis ◽  
Single Crystal ◽  
Ethyl Ester ◽  
Marine Sponge ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Methyl Esters ◽  
Chemical Degradation ◽  
X Ray ◽  
Great Australian Bight

A Sigmosceptrella sp. of sponge collected during trawling operations in the Great Australian Bight, Australia, has yielded a series of new norterpenes. These include a new bisnorditerpene, sigmosceptrin-A (5); two new norditerpenes, sigmosceptrin-B (14) and sigmosceptrin-C (15), isolated as their methyl esters (6) and (7) respectively; and an ethylated artefact, sigmosceptrin-B ethyl ester (8). Complete stereostructures were assigned to the sigmosceptrins by spectroscopic analysis, chemical degradation, derivatization, and by a single-crystal X-ray structural analysis. A biosynthetic pathway is proposed that requires a common biosynthetic precursor to both the sigmosceptrins and norterpene cyclic peroxides.

Crystal Structures of the 1:1 Adducts of N,N,N′,N′- Tetramethyl-o-phenylenediamine with Zinc(II) Bromide and Mercury(II) Bromide and Iodide

1985 ◽  
Vol 38 (10) ◽  
pp. 1521 ◽  
Author(s):  
CM Hughes ◽  
MC Favas ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Dimer Formation ◽  
X Ray

The 1:1 adducts of o-Me2N.C6H4.NMe2 (≡ L″) with ZnI2, HgBr2 and HgI2 are isomorphous and their crystal structures have been established by single-crystal X-ray diffraction methods, being refined to residuals of 0.045, 0.050, 0.035, for 1759, 1617, 1911 'observed' reflections respectively. Crystals are monoclinic P21/c,Z = 4, with a ~ 8.5, b ~ 21, c ~ 8 Ǻ, β ~ 95°. In L″ZnI2, {Zn-I} is 2.538, {Zn-N} 2.09 Ǻ, with I-Zn-I 115.36(6), N-Zn-N 84.6(3), and I-Zn-N 108.3(2)-118.3(2)°. In L″HgBr2, (Hg-Br) is 2.523, {Hg-N} 2.42 Ǻ, with Br-Hg-Br 123.04(8), N-Hg-N 73.2(4) and Br-Hg-N 98.9(3)-131.2(3)°. In L″HgI2, {Hg-I} is 2.661, {Hg-N} 2.44 Ǻ, with I-Hg-I 128.92 (3), N-Hg-N 72.8(3), and I-Hg-N 101.8(2)- 122.9(2). X-Hg-X angles are unexpectedly small and this is attributed to incipient dimer formation through an inversion centre, this tendency being greatest in (2) where the Hg…Br approach is 3.456(3) Ǻ and the immediate HgBr2N environment of the mercury is trigonal planar.

N-Benzoylthiocarbamoyl Amino Acid Ethyl Esters as Chelate Ligands for Transition Metal Ions

1998 ◽  
Vol 53 (9) ◽  
pp. 981-990 ◽  
Author(s):  
Frank Leßmann ◽  
Lothar Beyer ◽  
Rainer Richter ◽  
Reinhard Meusinger
Keyword(s):  
Amino Acid ◽  
Ethyl Ester ◽  
Optical Rotation ◽  
Transition Metal Ions ◽  
Crystal Structure Analysis ◽  
Ethyl Esters ◽  
Specific Optical Rotation ◽  
X Ray ◽  
Glycine Ethyl Ester ◽  
Benzoyl Isothiocyanate

Abstract The reactions of benzoyl isothiocyanate with amino acid ethyl esters (N-butyl glycine ethyl ester, (S)-(-)-proline ethyl ester) give N-benzoylthiocarbamoyl amino acid ethyl esters. Apart from the expected N-benzoylthiocarbamoyl (S)-(-)-proline ethyl ester the racemic N-benzoyl­ thiocarbamoyl (R)/(S)-proline ethyl ester is formed because of base catalyzed racemization of the educt (S)-(-)-proline ethyl ester during the reaction of (S)-(-)-proline ethyl ester hydrochloride with triethylamine. The structures of both compounds were established by X-ray crystal structure analysis and specific optical rotation measurements. The ligands yield neutral 2:1 chelates with NiII, CuII, PdII and PtII. The carboxylic oxygen atoms are not involved in the chelation. The ligands and the resultant complexes show configurational E/Z isomerism. In the case of the chelates of the racemic N-benzoylthiocarbamoyl (R)/(S)-proline ethyl ester, additional R/S isomerism is observed as shown by NMR spectroscopy.

scholarly journals Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

2018 ◽  
Vol 14 ◽  
pp. 1016-1020 ◽  
Author(s):  
Akira Yoshimura ◽  
Michael T Shea ◽  
Cody L Makitalo ◽  
Melissa E Jarvi ◽  
Gregory T Rohde ◽  
...  
Keyword(s):  
Single Crystal ◽  
Iodine Atom ◽  
Hypervalent Iodine ◽  
Covalent Bonds ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Good Solubility ◽  
Efficient Reagent ◽  
Heterocyclic Structure

A new bicyclic organohypervalent iodine heterocycle derivative of benziodazole was prepared by oxidation of 2-iodo-N,N’-diisopropylisophthalamide with m-chloroperoxybenzoic acid under mild conditions. Single crystal X-ray crystallography of this compound revealed a five-membered bis-heterocyclic structure with two covalent bonds between the iodine atom and the nitrogen atoms. This novel benziodazole is a very stable compound with good solubility in common organic solvents. This compound can be used as an efficient reagent for oxidatively assisted coupling of carboxylic acids with alcohols or amines to afford the corresponding esters or amides in moderate yields.

Catalyzing Synthesis of Chiral Nitrendipine

2012 ◽  
Vol 518-523 ◽  
pp. 3943-3946 ◽  
Author(s):  
Jian Yi Wu ◽  
Li Zhang ◽  
Li Ling Cai ◽  
Yang Zhang
Keyword(s):  
Methyl Ester ◽  
Single Crystal ◽  
Dicarboxylic Acid ◽  
Ethyl Ester ◽  
Phase Transfer ◽  
X Ray Diffraction ◽  
Chiral Synthesis ◽  
Chiral Phase ◽  
X Ray ◽  
Dihydropyridine Ring

This paper describes the chiral synthesis of R-2,6-dimethyl-4-(3-nitro phenyl)-1,4- dihydro-pyridine-3,5-dicarboxylic acid 3-ethyl ester 5-methyl ester (R-Nitrendipine) using chiral phase transfer catalyst. The structure of the obtained nitrendipine crystals was determined with single crystal X-ray diffraction. The crystal is monoclinic, with the space group of P21/c and unit cell constants of a=8.8577(15), b=15.581(3), c=12.999(2)Å, β=92.458(4)°, V=1792.3(5)Å3, Z=4, Dc =1.335g/cm3, F(000)=760. X-ray analysis reveals that the product is a chiral nitrendipine with R-configuration of the dihydropyridine ring. And measurement of polarimeter reveals that the synthesized nitrendipine is a chiral molecular.

scholarly journals Synthesis and comparative structural study of 2-(pyridin-2-yl)-1H-perimidine and its mono- and di-N-methylated analogues

2021 ◽  
Vol 77 (2) ◽  
pp. 96-100
Author(s):  
Paulina Kalle ◽  
Sergei V. Tatarin ◽  
Alexander Yu. Zakharov ◽  
Marina A. Kiseleva ◽  
Stanislav I. Bezzubov
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structural Study ◽  
Molecular Conformation ◽  
X Ray ◽  
Π Interactions ◽  
H Nmr ◽  
Mild Conditions

The title compounds, 2-(pyridin-2-yl)-1H-perimidine (C16H11N3; 1), 1-methyl-2-(pyridin-2-yl)-1H-perimidine (C17H13N3; 2), and 1,3-dimethyl-2-(pyridin-2-yl)-1H-perimidinium iodide (C18H16N3 +·I−; 3) were synthesized under mild conditions and their structures were determined by 1H NMR spectroscopy and single-crystal X-ray analysis. The N-methylation of the nitrogen atom(s) at the perimidine moiety results in a significant increase of the interplane angle between the pyridin-2-yl ring and the perimidine system. The unsubstituted perimidine (1) forms a weak intramolecular N—H...N bond that consolidates the molecular conformation. In the crystal structures of 1–3, the molecular entities all are assembled through π–π and C—H...π interactions.

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