Tricarbonylferrole iron tricarbonyl derivatives: formation from thiophenes and iron atoms in a CO atmosphere and fluxional behaviour

1977 ◽  
Vol 55 (20) ◽  
pp. 3509-3514 ◽  
Author(s):  
Tristram Chivers ◽  
Peter L. Timms
Keyword(s):  
Nmr Studies ◽  
Warm Up ◽  
Metal Atoms ◽  
Iron Tricarbonyl ◽  
Derivatives Of ◽  
C Nmr

Co-condensation of metal atoms (Cr, Fe) with thiophenes [Formula: see text] (R = R′ = H, Me; R = H, R' = Me) at −196 °C leads to desulphurization of the thiophene. Warm-up of the iron–thiophene co-condensate in a CO atmosphere produces derivatives of tricarbonylferrole iron tricarbonyl, C4H2RR′Fe2(CO)6. 13C nmr studies of these complexes show that the tricarbonyl ferrole unit is static from −95 °C to +60 °C, while the π-Fe(CO)3 group exhibits fluxional behaviour. Addition of dienes or Me3P in hexane to the iron–thiophene co-condensate at −196 °C yields thermally unstable red solutions on melting.

Seven-coordinate metal carbonyl derivatives of cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2

1976 ◽  
Vol 54 (16) ◽  
pp. 2548-2556 ◽  
Author(s):  
William R. Cullen ◽  
Lynn M. Mihichuk
Keyword(s):  
Metal Carbonyl ◽  
Activation Parameters ◽  
Nmr Studies ◽  
H Nmr ◽  
Carbonyl Derivatives ◽  
Derivatives Of ◽  
C Nmr

The seven-coordinate complexes (L—L)M(CO)3X2 (M = Mo, W; X = Br, I; (L—L) = cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2) were prepared and characterized. 1H and 13C nmr studies at 25 and −70 °C suggest that the complexes are nonrigid. Similarly 1H nmr studies indicate the seven-coordinate (L—L)LMo(CO)2Br2 complexes are also nonrigid. The (L—L)L2Mo(CO)Br2 complexes (L is a monodentate phosphite or phosphine) are rigid at 25 °C and nonrigid at higher temperatures. Activation parameters are calculated for the motion of two of the complexes and possible mechanisms are discussed.

In Search of New Approaches to Asymmetric Conjugate Addition: Screening Studies on the Use of [Zn(bpy*)X(R)] Reagents and α,β-Unsaturated Amide Michael Acceptors

2007 ◽  
Vol 72 (8) ◽  
pp. 1107-1121 ◽  
Author(s):  
Alexander J. Blake ◽  
Daniela Giunta ◽  
Jonathan Shannon ◽  
Maurizio Solinas ◽  
Francesca Walzer ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Conjugate Addition ◽  
Nmr Studies ◽  
Conjugate Additions ◽  
New Approaches ◽  
Michael Acceptors ◽  
Derivatives Of ◽  
Moderate Yield ◽  
C Nmr

Conjugate additions of [Zn(bpy*)Cl(Et)] (bpy* = 4,4'-di-tert-butyl-2,2'-bipyridine) to cyclohex-2-en-1-one are promoted by ZnMe2 in 88% ee but in moderate yield under CuI phosphoramidite catalysis. In the absence of ZnMe2 the [Zn(bpy*)Cl(Et)] is inactive indicating a Schlenk-type equilibrium. Other derivatives of [Zn(bpy*)Cl(R)] (R = Bu, 4-methylbenzyl), prepared in situ from [ZnCl(R)] and the bipyridine give low yields due to competing chloride abstraction. 13C NMR studies indicate facile organo-ligand exchange between [Zn(bpy*)(Et)2] and [Zn(bpy*)Cl2] complexes. In the presence of the bipyridine, [ZnBr(allyl)] disproportionates into [Zn(bpy*)Br2] and [Zn(bpy*)(allyl)2] species. In separate studies, simple (E)-MeCH=CHCONMeR (R = Me, OMe) α,β-unsaturated amides undergo asymmetric 1,4-addition of EtMgBr in 75-99% yield and 48-79% ee in the presence of the diphosphines JosiPhos or MeDuPhos and copper(I) sources.

scholarly journals Synthesis, Characterisation and Hydrolytic Reactions of the First Pentaisopropoxostannate Derivatives of Magnesium, Zinc and Cadmium

2007 ◽  
Vol 2007 (8) ◽  
pp. 458-460
Author(s):  
Jayshree Shahanl ◽  
Anirudh Singh
Keyword(s):  
Molecular Weight ◽  
Nmr Studies ◽  
Molar Ratios ◽  
Derivatives Of ◽  
C Nmr

Pentaisopropoxostannate derivatives of the types [{M[Sn(OPri)5](μ–Cl)}2] and [M{Sn(OPri)5}2] have been prepared by the reactions of MCl2 (M = Mg, Zn, and Cd) with NaSn(OPri)5 in 1:1 and 1:2 molar ratios, respectively, in benzene. All these derivatives have been characterised by elemental and isopropoxo group analyses, spectroscopic (IR, 1H and 13C NMR) studies, and molecular weight determinations. Two typical hydrolytic reactions of [Zn{Sn(OPri)5}2] have also been investigated.

Identification des configurations relatives d'alcools secondaires α-cyclopropylidéniques et α-vinylcyclopropaniques. Attribution de structure aux éthyl-6 diméthyl-2,4 oxa-3 bicyclo [3.1.01,5]hexanes

1979 ◽  
Vol 57 (17) ◽  
pp. 2314-2320 ◽  
Author(s):  
Maurice Vincens ◽  
Claude Dumont ◽  
Michel Vidal
Keyword(s):  
Basic Medium ◽  
Secondary Alcohols ◽  
Nmr Studies ◽  
Derivatives Of ◽  
C Nmr

During a stereochemical study of α-cyclic secondary alcohols, the relative configurations of the E, R*, and S* isomers of 1-(2-ethyl-3-ethylidene(1R*,2R*)cyclopropyl)ethanol was determined. Treatment in a basic medium of these secondary diastereomeric alcohols leads to the R* and S* isomers of 1-(2-ethyl-3-vinyl(1R*,2S*,3S*)cyclopropyl)ethanol. Cyclic oxymercuration of these cyclopropanoic derivatives yields the di-endo, di-exo, and exo–endo derivatives of 6-ethyl-2,4-dimethyl-3-oxabicyclo[3.1.0.1,5]hexane. The determination of the structure as bicyclic ethers, based on ir and 1H and 13C nmr studies, permits the assignment of the relative configurations of the vinylcyclopropanoic and cyclopropylidene alcohols. [Journal translation]

Thermal cyclocondensations of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino derivatives of 2-propenoic acid

1987 ◽  
Vol 52 (12) ◽  
pp. 2918-2925 ◽  
Author(s):  
Viktor Milata ◽  
Dušan Ilavský
Keyword(s):  
Uv Spectra ◽  
Propenoic Acid ◽  
Amino Derivatives ◽  
Derivatives Of ◽  
C Nmr ◽  
Ir And Uv Spectra

The cyclization of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino-2-cyano- and 2-ethoxycarbonyl-2-propenoate esters Ia, b-IVa, b under the conditions of the Gould-Jacobs reaction leads to angularly ring-fused substituted imidazo or triazolo[4,5-f] (V, VI) and [4,5-h] (VII, VIII) quinolines, respectively. The esters Vb-VIIIb have been transformed into the corresponding chloroderivatives Vc-VIIIc. 3-N(5-Benzimidazolyl and 5-benztriazolyl)amino-2-cyano-2-propenenitriles are cyclized in the presence of aluminium(III) chloride to give the aminoquinolines Vd, VId. The structure of the products has been characterized by their 1H, 13C NMR, IR, and UV spectra.

scholarly journals Structural Investigations of C-Nitrosobenzenes. Part 3.1 Solid-state and Solution 13C NMR Studies, and Crystal Structure of E-(4-CIC6H4NO)2

1999 ◽  
Vol 23 (3) ◽  
pp. 202-203
Author(s):  
Daniel A. Fletcher ◽  
Brian G. Gowenlock ◽  
Keith G. Orrell ◽  
David C. Apperley ◽  
Michael B. Hursthouse ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
13C Nmr ◽  
Nmr Studies ◽  
Structural Investigations ◽  
Nmr Data ◽  
C Nmr

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.

scholarly journals Structural differences between humic fractions from different soil types as determined by FT-IR and 13 C-NMR studies

1989 ◽  
Vol 81-82 ◽  
pp. 187-194 ◽  
Author(s):  
R. Fründ ◽  
H.-D. Lüdemann ◽  
F.J. Gonzalez-Vila ◽  
G. Almendros ◽  
J.C. del Rio ◽  
...  
Keyword(s):  
Soil Types ◽  
Nmr Studies ◽  
Structural Differences ◽  
Ft Ir ◽  
Humic Fractions ◽  
C Nmr

1,3-dipolar cycloaddition in the synthesis of glycoconjugates of natural chlorins and bacteriochlorins

2009 ◽  
Vol 13 (03) ◽  
pp. 336-345 ◽  
Author(s):  
Mikhail A. Grin ◽  
Ivan S. Lonin ◽  
Anna A. Lakhina ◽  
Elena S. Ol'shanskaya ◽  
Alexey I. Makarov ◽  
...  
Keyword(s):  
Triple Bond ◽  
Tautomeric Form ◽  
Click Reaction ◽  
Copper Cation ◽  
Water Soluble ◽  
Dipolar Cycloaddition ◽  
Nmr Studies ◽  
Metal Free ◽  
Cu Complex ◽  
Derivatives Of

Glucose-, galactose- and lactose-containing photosensitizers based on derivatives of chlorophyll a and bacteriochlorophyll a were synthesized with the use of [3+2] cycloaddition between sugar azides and triple bond derivatives of chlorins and bacteriochlorins. Unlike bacteriochlorin cycloimide, chlorin was detected to form a Cu -complex during the click reaction. An approach to the synthesis of metal-free glycosylated chlorins was developed with the use of "protection" by Zn 2+ cation and subsequent demetalation. It is based on the action of alkynyl chlorin e6 derivative Zn -complex, which is resistant to the substitution by copper cation. Bacteriochlorin p cycloimide conjugate with per-acetylated β-D-lactose was obtained and shown to become water-soluble after unblocking of the lactose hydroxy functions. NMR studies allowed for the elucidation of structure, tautomeric form and conformation of the obtained compounds.

Preparation of 2,3-Dideoxy-2,3-epimino and 3,4-Dideoxy-3,4-epimino Derivatives of 1,6-Anhydro-β-D-hexopyranoses by Mitsunobu Reaction

1998 ◽  
Vol 63 (6) ◽  
pp. 813-825 ◽  
Author(s):  
Jiří Kroutil ◽  
Tomáš Trnka ◽  
Miloš Buděšínský ◽  
Miloslav Černý
Keyword(s):  
Nmr Spectra ◽  
Mitsunobu Reaction ◽  
Derivatives Of ◽  
C Nmr

A series of new 2-, 3- and 4-benzylamino-2-, 3- and 4-deoxy derivatives of 1,6-anhydro-β-D-hexopyranoses were prepared from 1,6:2,3- and 1,6:3,4-dianhydro-β-D-hexopyranoses by treatment with benzylamine and converted into 2,3-(N-benzylepimino)-2,3-dideoxy- and 3,4-(N-benzylepimino)-3,4-dideoxy-β-D-hexopyranoses of the D-allo, D-galacto and D-talo configuration by Mitsunobu reaction. The structures of benzylamino and benzylimino derivatives were confirmed by 1H and 13C NMR spectra.

Triazene derivatives of (1,x-)diazacycloalkanes. Part VI. 3-({5,5-Dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines — Synthesis, characterization, and X-ray crystal structure

2006 ◽  
Vol 84 (10) ◽  
pp. 1294-1300 ◽  
Author(s):  
Keith Vaughan ◽  
Shasta Lee Moser ◽  
Reid Tingley ◽  
M Brad Peori ◽  
Valerio Bertolasi
Keyword(s):  
Crystal Structure ◽  
Significant Degree ◽  
Ion Trapping ◽  
Published Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Diazonium Ion ◽  
Derivatives Of ◽  
C Nmr

Reaction of a series of diazonium salts with a mixture of formaldehyde and 1,2-diamino-2-methylpropane affords the 3-({5,5-dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines (1a–1f) in excellent yield. The products have been characterized by IR and NMR spectroscopic analysis, elemental analysis, and X-ray crystallography. The X-ray crystal structure of the p-methoxycarbonyl derivative (1c) establishes without question the connectivity of these novel molecules, which can be described as linear bicyclic oligomers with two imidazolidinyl groups linked together by a one-carbon spacer. This is indeed a rare molecular building block. The molecular structure is corroborated by 1H and 13C NMR data, which correlates with the previously published data of compounds of types 5 and 6 derived from 1,3-propanediamine. The triazene moieties in the crystal of 1c display significant π conjugation, which gives the N—N bond a significant degree of double-bond character. This in turn causes restricted rotation around the N—N bond, which leads to considerable broadening of signals in both the 1H and 13C NMR spectra. The molecular ion of the p-cyanophenyl derivative (1b) was observed using electrospray mass spectrometry (ES + Na). The mechanism of formation of molecules of type 1 is proposed to involve diazonium ion trapping of the previously unreported bisimidazolidinyl methane (13).Key words: triazene, bistriazene, imidazolidine, synthesis, X-ray crystallography, NMR spectroscopy.

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