FTIR spectroscopic evidence for new isomers of 3-aminopyrazine-2-carboxylic acid formed in argon matrices upon UV irradiations

2021 ◽  
pp. 120158
Author(s):  
M. Pagacz-Kostrzewa ◽  
K. Mucha ◽  
W. Gul ◽  
M. Wierzejewska
Keyword(s):  
Carboxylic Acid ◽  
Spectroscopic Evidence ◽  
Argon Matrices

"Sideways" Bonded Dinitrogen in Matrix Isolated Cobalt Dinitrogen, CoN2

1973 ◽  
Vol 51 (4) ◽  
pp. 637-640 ◽  
Author(s):  
G. A. Ozin ◽  
A. Vander Voet
Keyword(s):  
Transition Metal ◽  
Metal Atom ◽  
Infrared Spectra ◽  
Transition Metal Atom ◽  
Spectroscopic Evidence ◽  
Isotopic Species ◽  
Argon Matrices

Infrared spectra are reported for matrix isolated cobalt dinitrogen isotopic species, Co14N2, Co14N15N and Co15N2, formed in the cocondensation reaction of atomic cobalt with dilute nitrogen–argon matrices at 10°K. The data provide the first unambiguous spectroscopic evidence for a dinitrogen molecule bonded in a "sideways" fashion to a transition metal atom.

5-Methoxyphenanthrene-4-carboxylic Acid

1989 ◽  
Vol 42 (6) ◽  
pp. 1007 ◽  
Author(s):  
RG Gillis ◽  
QN Porter
Keyword(s):  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Sodium Salt ◽  
Lead Tetraacetate ◽  
Spectroscopic Evidence

Lead tetraacetate oxidation of phenanthrene-4,5-dicarboxylic acid in acetonitrile with pyridine affords 5-hydroxyphenanthrene-4-carboxylic acid as its lactone , which can be methylated as the sodium salt, giving 5-methoxyphenanthrene-4-carboxylic acid, albeit in poor yield. New spectroscopic evidence (particularly 13C n.m.r.) confirms that 5-formylphenanthrene-4-carboxylic acid, which is an intermediate in the synthesis, exists as the lactol , 4-hydroxyphenanthro[4,5-cdeloxepin-G(4H)-one.

Constituents of Endiandra species. III. 4-[(E,E)-5'-Phenylpenta-2',4'-dien-1'-yl]tetra-cyclo[5,4,0,02,5,03,9]undec-10-ene-8-carboxylic acid from Endiandra introrsa (Lauraceae)

1982 ◽  
Vol 35 (3) ◽  
pp. 567 ◽  
Author(s):  
WM Bandaranayake ◽  
JE Banfield ◽  
DSC Black ◽  
GD Fallon ◽  
BM Gatehouse
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Title Compound ◽  
Spectroscopic Evidence ◽  
X Ray

The structure (5) is proposed for the title compound on the basis of chemical and spectroscopic evidence and on the X-ray crystal structure of the derivative 4-{(Y-methyl-1'',3''-dioxo-7''-phenyl- 1'',3'',3'',4'',7'',7a''-hexahydroisoindol-4''-yl)methyl}tetracyclo [5,4,0,02,5,O3,9] undec-10-ene-8-carboxylic acid (9c).

Binary Dioxygen Complexes of Nickel; Infrared Spectroscopic Evidence for Ni(O2) and (O2)Ni(O2) in Low Temperature Matrices

1972 ◽  
Vol 50 (22) ◽  
pp. 3746-3747 ◽  
Author(s):  
H. Huber ◽  
G. A. Ozin
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Nickel Atom ◽  
Isotope Substitution ◽  
Warm Up ◽  
Spectroscopic Evidence ◽  
Variable Concentration ◽  
Diffusion Controlled ◽  
Argon Matrices ◽  
And Diffusion

The cocondensation reaction of nickel atoms with oxygen or dilute oxygen–argon matrices at 4.2–10 °K gives rise to the first examples of binary transition metal dioxygen complexes. Variable concentration and diffusion controlled warm up studies and 16O2, 16O18O, 18O2 isotope substitution studies establish the stoichiometries of the dioxygen complexes of nickel to be Ni(O2) and (O2)Ni(O2). Both complexes have the dioxygen molecule(s) coordinated to the nickel atom in a "sideways" fashion.

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto
Keyword(s):  
Cerebrospinal Fluid ◽  
Carboxylic Acid ◽  
Fibrinolytic Activity ◽  
Clinical Implications ◽  
Trans Form ◽  
Plate Method ◽  
Blood Samples ◽  
Fibrin Plate ◽  
The Brain

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters

2019 ◽  
Author(s):  
Jiang Wang ◽  
Brian P. Cary ◽  
Peyton Beyer ◽  
Samuel H. Gellman ◽  
Daniel Weix
Keyword(s):  
Carboxylic Acid ◽  
Solid Support ◽  
Reaction Conditions ◽  
Decarboxylative Coupling ◽  
New Strategy ◽  
The Cross ◽  
Acyl Donors ◽  
Acid Esters

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

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