Réactions d’addition conjuguée d’organolithiens aux acides carboxyliquesα, β-insaturés

1999 ◽  
Vol 77 (1) ◽  
pp. 98-112 ◽  
Author(s):  
Jacques Mortier ◽  
Michel Vaultier ◽  
Barbara Plunian ◽  
Sourisak Sinbandhit
Keyword(s):  
Carboxylic Acids ◽  
Triple Bond ◽  
Nmr Spectra ◽  
Addition Reaction ◽  
Addition Reactions ◽  
X Ray ◽  
H Nmr ◽  
Unsaturated Carboxylic Acids ◽  
The Face ◽  
Trans Addition

In THF at -78°C, organolithium derivatives and unprotected α, β-unsaturated carboxylic acids give a conjugated addition reaction. Reactions of 1- and 2-naphthoic acids with various organolithium derivatives and electrophiles are reported. Two X-ray studies show that the reaction occurs with a good diastereoselectivity: the dilithiated enolate formed as an intermediate adds the electrophile exclusively via the face opposite to that of the organolithium. A study of the 1 H NMR spectra of the products obtained shows that these compounds adopt a preferred conformation in solution. The protonolysis of the intermediate enolate by trifluoroacetic acid in an inverted mode gives rise to the formation of 1,2-disubstituted dihydronaphthalenes. With acyclic α, β-unsaturated carboxylic acids, the diastereoselectivity of the reaction is marginal. With secondary butyllithium, the protonolysis of the intermediate enolates gives a 1,4-addition and an average diastereoselectivity. Reaction of phenylpropiolic acid with butyllithium gives rise to the formation of a product resulting from a trans addition to the triple bond; the organolithium derivative adds in α to the carboxylic group.Key words: 1,4-addition reactions, carboxylic acids, organolithium derivatives.[Journal Translation]

New type of addition to 5-substituted 4-arylidene-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorates. Preparation of 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes

1986 ◽  
Vol 51 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Tibor Gracza ◽  
Zdeněk Arnold ◽  
Jaroslav Kováč
Keyword(s):  
Nmr Spectra ◽  
Addition Reaction ◽  
H Nmr ◽  
Organic Bases ◽  
New Type

4-Arilidene-5-(N,N-dimethyliminium)-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorate I undergoes a 1,4-addition reaction with organic bases under re-formation of the furan nucleus; this behaviour has been utilized in the preparation of new 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes II, III. The structure of the prepared compounds has been confirmed by 13C and 1H NMR spectra.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Organometallic oxides: preparation of the cluster [(η-C5Me5)Mo]4O7 by reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O)

2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu
Keyword(s):  
Nmr Spectra ◽  
Chloroform Solution ◽  
X Ray Diffraction ◽  
Broad Resonance ◽  
Nmr Spectrum ◽  
X Ray ◽  
Temperature Range ◽  
H Nmr ◽  
Tributyltin Hydride ◽  
Effective Moment

Reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(η-C5Me5)Mo]4O7, with [(η-C5Me5)Mo(O)(μ-O)]2 as a co-product. [(η-C5Me5)Mo]4O7 was characterized by X-ray diffraction, mass spectrometry, 1H NMR and IR spectroscopies, and magnetism. Crystals of [(η-C5Me5)Mo]4O7 contained a tetrahedral [(η-C5Me5)Mo]4 unit (Mo-Mo = 2.909 (3) Å) with the Mo4O7 core having the structure Mo4(μ2-O(b))3(µ2-O(c))3(µ3-O(a)) (3). Microcrystalline samples of [(η-C5Me5)Mo]4O7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 μB at 300 K. [(η-C5Me5)Mo]4O7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 µB at 298 K. The 1H NMR spectrum showed a broad resonance at 16.3 ppm (Δν 1/2 = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (Δν 1/2 = 5 Hz). The magnetism and NMR spectra showed that [(η-C5Me5)Mo]4O7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.Key words: cluster, cyclopentadienyl, molybdenum, oxide, paramagnetism.

scholarly journals Darstellung und Charakterisiening der Spezies R-C7H7Mo(CO)3 und die Röntgenstrukturanalyse von / Synthesis and Characterisation of the Species R-C7H7Mo(CO)3 and the X-ray Structure Determination of

1978 ◽  
Vol 33 (4) ◽  
pp. 361-365 ◽  
Author(s):  
Margret Sommer ◽  
Klaus Weidenhammer ◽  
Henning Wienand ◽  
Manfred L. Ziegler
Keyword(s):  
Carbon Atom ◽  
Structure Determination ◽  
Nmr Spectra ◽  
X Ray ◽  
Ethyl Group ◽  
H Nmr

The species R−C7H7Mo(CO)3 (R=−CH2COCH3,−CH(CH3)COCH3,−CH(CH)(CH3)2COCH3) have been synthesized by electrolysing [η7-C7H7Mo(CO)3]+, η7-C7H7Mo(CO)2Br and the dimers [C7H7Mo(CO)3]2 and (C7H7)2Mo(CO)3, respectively, in suitable ketones and HBr. 1H NMR spectra and the X-ray structure determination of (CH3−CO−CH(CH3)−C7H7)Mo(CO)3 revealed the CH3−CO−CH(CH3)-group being bonded to the cycloheptatriene ligand via the α-carbon atom of the ethyl group.

Zinc Complexes of Dimethyl(phthalimidomethyl)phosphine Oxide

1994 ◽  
Vol 49 (2) ◽  
pp. 258-262
Author(s):  
Sabi Varbanov ◽  
Elena Russeva ◽  
Andrei Ganchev
Keyword(s):  
Oxygen Atom ◽  
Phosphine Oxide ◽  
Nmr Spectra ◽  
Zinc Complexes ◽  
X Ray ◽  
H Nmr ◽  
Infrared Spectral ◽  
Phosphoryl Oxygen ◽  
Halide Complexes ◽  
Powder Analysis

A series o f zinc complexes of dimethyl(phthalimidomethyl)phosphine oxide (DPPO, L) have been synthesized: ZnX2L2, where X = Cl, Br, I or NO3. The complexes are characterized by elemental analysis, infrared and 1H NMR spectra and X-ray powder analysis. Infrared spectral data show that L is coordinated to zinc via the phosphoryl oxygen atom. The zinc halide complexes are found to be isostructural, while the pattern o f Zn(NO3)2L2 differs considerably from those o f halide complexes.

scholarly journals Atran-analoge Verbindungen des Typs / Atrane Analogous Compounds of the Type

1984 ◽  
Vol 39 (3) ◽  
pp. 341-351 ◽  
Author(s):  
Joseph Grobe ◽  
Gerald Henkel ◽  
Bernt Krebs ◽  
Nikolaos Voulgarakis
Keyword(s):  
Structure Analysis ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Trigonal Bipyramid ◽  
Angular Distortion ◽  
Type I ◽  
Tetrahedral Coordination ◽  
Cage Compounds ◽  
X Ray ◽  
H Nmr

Heterocyclic cage compounds of type I (compounds 8-10) have been prepared by condensation reactions of 1,2,2-trifunctional disilanes Me(R)XSiSiMeX2 (R = Me, Ph, OEt; X = NMe2, OEt) with triethanolamine using the “Dilution Principle”. The starting compounds are obtained by Si-Me cleavage of Si2Me6 with acetylchloride/AlCl3 followed by either aminolysis with HNMe2 or alcoholysis with EtOH. 1H NMR spectra indicate N→Si(1) intraction with the more acidic Si atom in 8 and 9. This result is proved by the X-ray structure analysis of 8 (monoclinic, P21/c; a = 7,088(2), b = 15,070(4), c = 12,701(4) Å, β = 104,96(2) at -130 °C, Z = 4); the Si(1)···N distance is found to be 2,768 Å , connected with a significant angular distortion of the tetrahedral coordination around Si(1) towards a trigonal bipyramid. In compound 10, too, N→Si(1) coordination is observed at room temperature in spite of almost equal acidity for both Si atoms. This can be explained by the preference of 5- over 6-membered chelating ring systems. At higher temperatures the 1H NMR spectra show a fluctuation of the N-donor between the two Si centres.

scholarly journals Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

2018 ◽  
Vol 14 ◽  
pp. 3011-3017
Author(s):  
Akın Sağırlı ◽  
Yaşar Dürüst
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Synthetic Route ◽  
X Ray ◽  
H Nmr ◽  
2D Nmr Spectra ◽  
Tof Ms ◽  
C Nmr

The present work describes an unfamiliar reaction of 5-(chloromethyl)-3-substituted-phenyl-1,2,4-oxadiazoles with KCN affording trisubstituted 1,2,4-oxadiazol-5-ylacetonitriles and their parent alkanes, namely, 1,2,3-trisubstituted-1,2,4-oxadiazol-5-ylpropanes. To the best of our knowledge, the current synthetic route leading to decyanated products will be the first in terms of a decyanation process which allows the transformation of trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title compounds were identified by means of IR, 1H NMR, 13C NMR, 2D NMR spectra, TOF–MS and X-ray measurements.

scholarly journals New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

2007 ◽  
Vol 62 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Stephan W. Kohl ◽  
Katharina Kuse ◽  
Markus Hummert ◽  
Herbert Schumann ◽  
Clemens Mügge ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Nmr Spectra ◽  
Acid Ethyl Ester ◽  
Affinity Tags ◽  
X Ray ◽  
H Nmr ◽  
Synthetic Routes ◽  
New Compounds ◽  
C Nmr

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

Das 7,8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ5-phosphaspiro[4.4]nonanyl-Kation: Röntgenstrukturanalyse und temperaturabhängige 1H-NMR-Spektren: The 7, 8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ).5-phosphaspiro[4.4]nonanyl Cation: X-Ray Crystal Structure Determination and Variable 1H NMR Spectra

1992 ◽  
Vol 47 (6) ◽  
pp. 755-759 ◽  
Author(s):  
Thomas Kaukorat ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
1H Nmr ◽  
Nmr Spectra ◽  
Crystal Structure Analysis ◽  
Acceptor Interaction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Trigonal Bipyramidal ◽  
Donor Acceptor

The 1H NMR spectrum of the spirophosphorane 3 at room temperature indicates dynamic behaviour of the cation. The low-temperature 1H NMR spectra of 3 exhibit two sets of doublets for the protons of the diastereotopic N(CH3)2 groups. The free enthalpy of activation for the dynamic process was determined (58.6 KJ/mole). In the reaction of 3 with sodium tetraphenylborate the crystalline compound, 4, involving the non-coordinating anion, [B(C6H5)4]-, was obtained. The X-ray crystal structure analysis of 4 reveals the presence of a five-membered ring, formally as a result of intramolecular donor-acceptor interaction between the nitrogen atom of the N(CH3)2 group and phosphorus. The geometry at phosphorus deviates somewhat from ideal trigonal bipyramidal.

Sign in / Sign up

Export Citation Format

Share Document