Full Cleavage of C≡C Bond in Electron-Deficient Alkynes via Reaction with Ethylenediamine

2017 ◽  
Vol 70 (4) ◽  
pp. 421 ◽  
Author(s):  
Sergei F. Vasilevsky ◽  
Maria P. Davydova ◽  
Victor I. Mamatyuk ◽  
Nikolay Tsvetkov ◽  
Audrey Hughes ◽  
...  
Keyword(s):  
Aryl Halides ◽  
The Other ◽  
Keto Group ◽  
Sonogashira Coupling ◽  
Methyl Group ◽  
Concomitant Reduction

Reaction of 1,2-diaminioethane (ethylenediamine) with electron-deficient alkynes leads to full scission of the C≡C bond even in the absence of a keto group directly attached to the alkyne. This process involves oxidation of one of the alkyne carbons into C2 of a 2-R-4,5-dihydroimidazole with the concomitant reduction of the other carbon to a methyl group. The sequence of Sonogashira coupling with the ethylenediamine-mediated fragmentation described in this work can be used for selective formal substitution of halogen in aryl halides by a methyl group or a 4,5-dihydroimidazol-2-yl moiety.

STEROIDS AND RELATED PRODUCTS: VII. THE SYNTHESIS OF 17α-METHYLCORTICOSTERONE

1957 ◽  
Vol 35 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Ch. R. Engel
Keyword(s):  
Ethylene Glycol ◽  
Biologically Active ◽  
The Other ◽  
Keto Group ◽  
Methyl Group ◽  
Other Hand ◽  
Hydrolysis Of

The synthesis of 17α-methylcorticosterone, a new biologically active homologue of corticosterone and analogue of cortisol, is described. In the course of the work it was observed that the 17-methyl group greatly impeded both the formation and the hydrolysis of a 20-ketal. On the other hand, evidence was obtained that the 11-keto group is not completely unreactive towards ethylene glycol, in the presence of p-toluenesulphonic acid.

Selective cyclization modes of methyl 3′-heteroarylamino-2′-(2,5-dichlorothiophene-3-carbonyl)acrylates. Synthesis of model (thienyl)pyrazolo- and triazolo[1,5-α]pyrimidines

2020 ◽  
Vol 75 (12) ◽  
pp. 1037-1042
Author(s):  
Nuha I. Sweidan ◽  
Mustafa M. El-Abadelah ◽  
Musa Z. Nazer ◽  
Wolfgang Voelter
Keyword(s):  
Spectral Data ◽  
The Other ◽  
Keto Group ◽  
Other Hand ◽  
Selective Displacement ◽  
New Compounds

AbstractInteraction of methyl 3-ethoxy-2-(2,5-dichloro-3-thenoyl)acrylate (I) with 3-aminopyrazole and 3-amino-1,2,4-triazole generated the respective pyrazolo[1,5-α]pyrimidine (4) and triazolo[1,5-α]pyrimidine (7). The formation of 4 entails selective and consecutive displacement of the 3-ethoxy and methoxy (ester) anions in I by 3-NH2 and 1-NH of 3-aminopyrazole. On the other hand, the formation of 7 implies selective displacement of 3-ethoxy in I by the ring-NH followed by cyclocondensation involving the keto group in I and 3-NH2 of aminotriazole. This latter selective displacement sequence is also followed by 3-amino-5-hydroxypyrazole in its reaction with I. The structures of the new compounds are supported by microanalytical and spectral data.

scholarly journals The Utility of Sonogashira Coupling Reaction for the Derivatization of Aryl Halides with Fluorescent Alkyne

2018 ◽  
Vol 34 (10) ◽  
pp. 1183-1188 ◽  
Author(s):  
Naoyuki YASAKA ◽  
Naoya KISHIKAWA ◽  
Takumi HIGASHIJIMA ◽  
Kaname OHYAMA ◽  
Naotaka KURODA
Keyword(s):  
Coupling Reaction ◽  
Aryl Halides ◽  
Sonogashira Coupling ◽  
Sonogashira Coupling Reaction

Sonogashira Coupling of Aryl Halides Catalyzed by Palladium on Charcoal

2003 ◽  
Vol 68 (8) ◽  
pp. 3327-3329 ◽  
Author(s):  
Zoltán Novák ◽  
András Szabó ◽  
József Répási ◽  
András Kotschy
Keyword(s):  
Aryl Halides ◽  
Sonogashira Coupling

scholarly journals Efficient Access to Materials-Oriented Aromatic Alkynes via the Mechanochemical Sonogashira Coupling of Solid Aryl Halides with Large Polycyclic Conjugated Systems

2021 ◽  
Author(s):  
Yunpeng Gao ◽  
Chi Feng ◽  
Tamae Seo ◽  
Koji Kubota ◽  
Hajime Ito
Keyword(s):  
Organic Materials ◽  
Aryl Halides ◽  
Sonogashira Coupling ◽  
Important Research ◽  
Conjugated Systems ◽  
Efficient Access ◽  
Indispensable Tool

Sonogashira coupling represents an indispensable tool for the preparation of organic materials that contain C(sp)–C(sp2) bonds. Improving the efficiency and generality of this methodology has long been an important research...

Splanchnic hemodynamic response to passive hyperventilation

1975 ◽  
Vol 38 (1) ◽  
pp. 156-162 ◽  
Author(s):  
E. E. Johnson
Keyword(s):  
Surface Area ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Respiratory Alkalosis ◽  
The Other ◽  
Capillary Surface ◽  
O2 Uptake ◽  
O2 Extraction ◽  
Concomitant Reduction ◽  
Mesenteric Vascular Resistance

Two groups of anesthetized, splenectomized, and paralyzed dogs were hyperventilated (Vt 40 ml/kg). Normocapnia was maintained in one group (mean Paco2 37.6 mm”h′g, mean p”h ′7.41) and respiratory alkalosis (mean Paco2 8 mmHg, mean pH 7.75) in the other. Splanchnic hemodynamic responses were similar in both groups. Average hepatic venous pressure increased from 3.2 to 6.4 mmHg in the normocapnic group and from 3.8 to 7.7 mmHg in the hypocapnic group. Average portal venous pressure increased from 10.7 to 12.0 mmHg and 10.8 to 12.7 mmHg in the normocapnic and hypocapnic groups, respectively. Mesenteric vascular resistance increased in 93 per cent of dogs. A decrease in functional intestinal capillary surface area during hyperventilation was indicated by a significant reduction in mesenteric Vo2 (from 15 to 11 ml/min, average 30 per cent), and a concomitant reduction in mesenteric O2 extraction ratio. Changes in mesenteric Vo2 were reflected in calculated splanchinic Vo2. Hepatic O2 uptake was essentially unchanged by tidal hyperventilation with or without hypocapnia.

Absolute stereochemistry of calopiptin

1968 ◽  
Vol 21 (8) ◽  
pp. 2095 ◽  
Author(s):  
JB Mc Alpine ◽  
NV Riggs ◽  
PG Gordon
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
The Other ◽  
Methyl Groups ◽  
Lower Field ◽  
Methyl Group ◽  
Low Field ◽  
Absolute Stereochemistry ◽  
Resolution Mass

The α,α?-diaryl-β,β-dimethyltetrahydrofurenoid lignan, calopiptin, from Piptocalyx moorei has been converted by demethylenation and methylation into veraguensin, now also isolated from Trimenia papuana (both species, family Trimeniaceae). Ozonolysis yields (-)-2,3-dimethylsuocinic acid which establishes the absolute trans configuration of the methyl groups. The benzylic proton giving a signal at low field from the other in the p.m.r, spectrum is assigned as trans to the adjacent methyl group by shielding and spin-decoupling arguments. The signal moves to even lower field on nitration of one of the aryl groups, identified as 3,4-dimethoxyphenyl by competitive nitration experiments and high-resolution mass spectrometry. Calopiptin is 2R-(3,4-dimethoxyphenyl)-3S,4S-dimethyl-5S-(3,4-methylenedioxyphenyl)tetrahydrofuran.

Synthesis and Crystal Structure of 4,7-bis (2-thienylethynyl)-2,1,3-benzothiadiazole

2002 ◽  
Vol 2002 (10) ◽  
pp. 511-513 ◽  
Author(s):  
Chitoshi Kitamura ◽  
Kakuya Saito ◽  
Mikio Ouchi ◽  
Akio Yoneda ◽  
Yoshiro Yamashita
Keyword(s):  
Crystal Structure ◽  
Thiophene Ring ◽  
The Other ◽  
Sonogashira Coupling ◽  
Synthesis And Crystal Structure

4,7-Bis(2-thienylethynyl)-2,1,3-benzothiadiazole was prepared by Sonogashira coupling. The crystal structure showed that one thiophene ring is coplanar and the other is perpendicular to the benzothiadiazole ring.

BEZIEHUNGEN ZWISCHEN SUBSTITUTION IM RING A UND ABBAU IM STOFFWECHSEL BEI VERWANDTEN DES TESTOSTERONS

1962 ◽  
Vol 41 (4) ◽  
pp. 494-506 ◽  
Author(s):  
H. Langecker
Keyword(s):  
Double Bond ◽  
Ring System ◽  
Keto Group ◽  
Hydroxyl Group ◽  
Methyl Group ◽  
Structural Peculiarities ◽  
Metabolic Degradation ◽  
The Difference ◽  
Testosterone Metabolites ◽  
Derivatives Of

ABSTRACT Judging from the metabolites found in the urine, 1-methyl-androst-1-en-17β-ol-3-one (methenolone) and testosterone are metabolized in a different manner. For further clarification, other derivatives of testosterone with modifications in Ring A were investigated with regard to the oxidation of the 17-hydroxyl group. The production of urinary 17-ketosteroids decreased in the following sequence: testosterone; 1α-methyltestosterone and androstan-17β-ol-3-one; 1β-methyl-androstan-17β-ol-3-one; 2α-methyl-androstan-17β-ol-3-one and androst-1-en-17β-ol-3-one; 1α-methyl-androstan-17β-ol-3-one; 1-methyl-androsta-1,4-dien-17β-ol-3-one; 1,17α-dimethyl-androst-1-en-17β-ol-3-one and 1 -methyl-androst-1 -en-17β-ol-3-one (methenolone). The difference in metabolic degradation is also demonstrated in the fractionation of the urinary ketones. While after the administration of testosterone practically only hydrogenated 17-ketones are observed in the urine, the unchanged compound is still traceable in remarkable quantities after the administration of methenolone, along with minor quantities of the corresponding diketone. Testosterone-metabolites here are absent, whereas they represent the major substances present after the administration of androst-1-en-17β-ol-3-on. Following the administration of 1α-methyltestosterone only hydrogenated 17-ketones are detected which are still partly methylated. The 1-methyl-group and the Δ 1-double-bond seem to be responsible for the inhibition of the oxidation of methenolone in the 17-position. In addition, the hydrogenation of the double-bond and the reduction of the 3-keto-group are inhibited, obviously on account of the same structural peculiarities. The demethylation of methenolone is also inhibited. Any change in the steroid ring system forms a new substrate, thus producing new conditions for the enzymatic attack in the metabolic degradation.

scholarly journals Crystal structure of dichlorido{4-[(E)-(methoxyimino-κN)methyl]-1,3-thiazol-2-amine-κN3}palladium(II)

2015 ◽  
Vol 71 (1) ◽  
pp. m10-m11 ◽  
Author(s):  
Viktorita V. Dyakonenko ◽  
Olga O. Zholob ◽  
Svitlana I. Orysyk ◽  
Vasily I. Pekhnyo
Keyword(s):  
Bidentate Ligand ◽  
The Other ◽  
Mean Deviation ◽  
Amino Group ◽  
Methyl Group ◽  
Square Planar ◽  
The Mean ◽  
Van Der Waals Radii ◽  
Cl Atoms ◽  
Coordination Plane

In the title compound, [PdCl2(C5H7N3OS)], the PdIIatom adopts a distorted square-planar coordination sphere defined by two N atoms of the bidentate ligand and two Cl atoms. The mean deviation from the coordination plane is 0.029 Å. The methyl group is not coplanar with the plane of the metallacycle [torsion angle C—O—N—C = 20.2 (4)°]. Steric repulsion between the methyl group and atoms of the metallacycle is manifested by shortened intramolecular H...C contacts of 2.27, 2.38 and 2.64 Å, as compared with the sum of the van der Waals radii of 2.87 Å. The amino group participatesviaone H atom in the formation of an intramolecular N—H...Cl hydrogen bond. In the crystal, the other H atom of the amino group links moleculesviabifurcated N—H...(Cl,O) hydrogen bonds into chains parallel to [001].

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