scholarly journals Synthesis and Characterization of Unsymmetrical Double-Decker Siloxane (Basket Cage)

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4252 ◽  
Author(s):  
Rungthip Kunthom ◽  
Nobuhiro Takeda ◽  
Masafumi Unno
Keyword(s):  
29Si Nmr ◽  
Cage Compounds ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Double Decker ◽  
Novel Structure ◽  
The One ◽  
First Time

The one-pot synthesis of an unsymmetrical double-decker siloxane with a novel structure via the reaction of double-decker tetrasodiumsilanolate with 1 equiv. of dichlorotetraphenyldisiloxane in the presence of an acid is reported herein for the first time. The target compound bearing all phenyl substituents on the unsymmetrical siloxane structure was successfully obtained, as confirmed by 1H-NMR, 13C-NMR, 29Si-NMR, IR, MALDI-TOF, and X-ray crystallography analyses. Additionally, the thermal properties of the product were evaluated by TG/DTA and compared with those of other siloxane cage compounds.

scholarly journals Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties

2013 ◽  
Vol 9 ◽  
pp. 2202-2215 ◽  
Author(s):  
Catalin V Maftei ◽  
Elena Fodor ◽  
Peter G Jones ◽  
M Heiko Franz ◽  
Gerhard Kelter ◽  
...  
Keyword(s):  
Natural Product ◽  
Synthesis And Characterization ◽  
Aminobenzoic Acid ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Quisqualic Acid ◽  
Oxobutanoic Acid

Taking into consideration the biological activity of the only natural products containing a 1,2,4-oxadiazole ring in their structure (quisqualic acid and phidianidines A and B), the natural product analogs 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)pyrrolidine-2,5-dione (4) and 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)-1H-pyrrole-2,5-dione (7) were synthesized starting from 4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)aniline (1) in two steps by isolating the intermediates 4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobutanoic acid (3) and (Z)-4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobut-2-enoic acid (6). The two natural product analogs 4 and 7 were then tested for antitumor activity toward a panel of 11 cell lines in vitro by using a monolayer cell-survival and proliferation assay. Compound 7 was the most potent and exhibited a mean IC50 value of approximately 9.4 µM. Aniline 1 was synthesized by two routes in one-pot reactions starting from tert-butylamidoxime and 4-aminobenzoic acid or 4-nitrobenzonitrile. The structures of compounds 1, 2, 4, 5 and 6 were confirmed by X-ray crystallography.

scholarly journals Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

2019 ◽  
Vol 15 ◽  
pp. 1347-1354
Author(s):  
Andrew T King ◽  
Hugh G Hiscocks ◽  
Lidia Matesic ◽  
Mohan Bhadbhade ◽  
Roger Bishop ◽  
...  
Keyword(s):  
Single Crystal ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
One Pot ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
X Ray Crystallography ◽  
The One ◽  
Close Contacts

The one-pot reaction of 2,6-bis(diphenylmethyl)-4-methoxyaniline with tert-butylnitrite, BTEAC and DABSO in the presence of CuCl2 provided an unexpected 3H-indazole product 8. The structure of the compound was determined by HRMS, IR, NMR and further confirmed by single crystal X-ray crystallography. The compound crystallises in the triclinic P-1 space group, with unit cell parameters a = 9.2107 (4), b = 10.0413 (5), c = 14.4363 (6) Å, α = 78.183 (2), β = 87.625 (2), γ = 71.975 (2)°. The formation of 8 proceeded through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate 9. The molecules of 8 are organised by edge–face Ar–H···π, face–face π···π, and bifurcated OCH2–H···N interactions. In addition to these, there are Ar–H···H–Ar close contacts, (edge–edge and surrounding inversion centres) arranged as infinite tapes along the a direction.

Syntheses and characterization of a series of asymmetric porphyrins containing an 8-ethoxycarbonyl-1-naphthyl group

2013 ◽  
Vol 17 (05) ◽  
pp. 392-398 ◽  
Author(s):  
Gaohui Xu ◽  
Jiaxun Jiang ◽  
Chuanjiang Hu
Keyword(s):  
Solid State ◽  
Ring Current ◽  
Ester Group ◽  
Porphyrin Ring ◽  
Nmr Studies ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Steric Property

Using aldehydes with different substituents of the aryl groups, we have synthesized a series of asymmetric porphyrins containing an 8-ethoxycarbonyl-1-naphthyl group by one-pot reactions. Our studies suggest the steric property of substituents is the major factor to affect the reaction yields, the steric hindrance is unfavorable for such reaction. Compared with those para-substituted species, NMR studies of 2,6-substituted species show upfield shifts for their NH and ethyl protons, downfield shifts for their pyrrole protons, which is probably due to the decrease of porphyrin ring current. Three of them have been characterized by X-ray crystallography. Structures show that the ester group is hanging over the porphyrin plane, compound 3 and 4 have much different core conformations from compound 2, which is probably due to the π–π interactions in the solid state.

Pyridinium ylides in the one-pot synthesis of a new quinoline/indolizine hybrid

2015 ◽  
Vol 70 (12) ◽  
pp. 885-887 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Abdelmalek Bouraiou ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Aissa Chibani
Keyword(s):  
Pyridine Ring ◽  
Membered Ring ◽  
Dimethyl Acetylenedicarboxylate ◽  
One Pot ◽  
X Ray ◽  
Pyridinium Ylides ◽  
The One ◽  
Methylene Group ◽  
Pyridinium Ylide

AbstractThe reaction of 1-(quinolin-2-ylmethyl)pyridinium ylide with dimethyl acetylenedicarboxylate was investigated. The X-ray crystallographic characterization of the new dimethyl 3-(quinolin-2-yl)indolizine-1,2-dicarboxylate (2) shows the formation of a five-membered ring between the pyridine ring and the methylene group.

An oxidative carbon–carbon bond-forming reaction proceeds via an isolable iminium ion

2011 ◽  
Vol 83 (3) ◽  
pp. 655-665 ◽  
Author(s):  
Althea S.-K. Tsang ◽  
Paul Jensen ◽  
James M. Hook ◽  
A. Stephen K. Hashmi ◽  
Matthew H. Todd
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
One Pot ◽  
X Ray ◽  
Bond Forming ◽  
X Ray Crystallography ◽  
Carbon Carbon Bond ◽  
Iminium Ion ◽  
Reaction Proceeds ◽  
First Time

The mechanism of our previously reported DDQ-mediated oxidative C–C bond-forming reaction is investigated. We are able to trap and characterize an iminium ion intermediate with X-ray crystallography, elemental analysis, and solid-state NMR spectroscopy; to our knowledge this is the first time this putative intermediate ion has been directly observed in such cross-dehydrogenative couplings (CDCs). The intermediate can be reacted with a range of nucleo-philes, including a malonate that is not amenable to a one-pot reaction protocol.

1-(2′-Benzimidazolylmethyl)-pyridinium ylide in the one-pot synthesis of indolizine and benzimidazo[1,2-a]pyridine derivatives

2015 ◽  
Vol 70 (8) ◽  
pp. 555-561 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Abdelmalek Bouraiou
Keyword(s):  
Nmr Spectroscopy ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyridine Derivatives ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimethyl Maleate ◽  
The One ◽  
Pyridinium Ylide

AbstractFour indolizine derivatives were obtained via 1,3-dipolar cycloaddition reaction of 1-(2′-benzimidazolylmethyl)pyridinium ylide with various electron-deficient alkynes. The reaction of this pyridinium N-ylide with dimethyl maleate gave an unexpected methyl 1-oxo-benzimidazo[1,2-a]pyridine-3-carboxylate. The structures of all reported compounds have been examined by X-ray crystallography and NMR spectroscopy.

Michael-Michael Aldol Reaction of Chalcones with Cyanoacetylurea and Cyanoacetylpiperidine

1995 ◽  
Vol 60 (4) ◽  
pp. 594-604 ◽  
Author(s):  
Hani D. Tabba ◽  
Nidal M. Yousef ◽  
Mohammad M. Al-Arab
Keyword(s):  
Room Temperature ◽  
Reaction Products ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Anhydrous Alcohol ◽  
One Pot Condensation ◽  
The One ◽  
Sodium Alkoxide ◽  
C Nmr

Several highly substituted cyclohexane derivatives were synthesized by the one-pot condensation of chalcones and cyanoacetylurea (2 : 1) using sodium alkoxide in anhydrous alcohol at room temperature. The structure of the reaction products was established by infrared, 1H and 13C NMR spectroscopy as well as by their elemental analysis. Single crystal X-ray crystallography shows the presence of the cyclohexane moiety.

scholarly journals Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

2021 ◽  
Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Structural Characterization ◽  
Schiff Base Ligand ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

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