scholarly journals Di-tungsten Bis-carbene Complexes Linked by Condensed Heteroaromatic Spacers

2007 ◽  
Vol 62 (3) ◽  
pp. 419-426 ◽  
Author(s):  
Marilé Landmana ◽  
Helmar Görls ◽  
Chantelle Crause ◽  
Hubert Nienaber ◽  
Andrew Olivier ◽  
...  
Keyword(s):  
Structural Features ◽  
Crystallographic Data ◽  
Reaction Conditions ◽  
Carbene Complexes

The 2,7-dilithiated substrates of 3,6-dimethylthieno[3,2-b]thiophene, N,N′-dimethylpyrrolo[3,2- b]pyrrole and N-methylthieno[3,2-b]pyrrole were reacted with W(CO)6 to give, after subsequent alkylation with Et3OBF4, the ditungsten biscarbene complexes [(CO)5W{C(OEt)XXC(OEt)} W(CO)5] (XX = condensed heteroaromatic spacers). Sites of attack during the dilithiation of the condensed rings were studied and compared, and the yields of the desired ditungsten biscarbene complexes optimized by changing the reaction conditions according to the role of the heteroatoms in the rings. The crystallographic data of the three ditungsten biscarbene complexes are reported and their structural features compared. The methyl substituents on the condensed heteroaromatic rings play an important role in determining the molecular configurations.

scholarly journals Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

2020 ◽  
Vol 16 ◽  
pp. 509-514 ◽  
Author(s):  
Anna R Bockman ◽  
Jeffrey M Pruet
Keyword(s):  
Reaction Kinetics ◽  
Structural Features ◽  
Product Formation ◽  
Reaction Conditions ◽  
First Order ◽  
First Order Kinetics ◽  
Synthetic Utility ◽  
Pseudo First Order ◽  
Pteridine Derivatives

The synthetic utility of pterins is often hampered by the notorious insolubility of this heterocycle, slowing the development of medicinally relevant pteridine derivatives. Reactions which expedite the development of new pterins are thus of great importance. Through a dual role of diazabicycloundecene (DBU), 7-carboxymethylpterin is converted to the soluble DBU salt, with additional DBU promoting an ester-to-amide transformation. We have explored this reaction to assess its scope and identify structural features in the amines which significantly affect success, monitored the reaction kinetics using a pseudo-first order kinetics model, and further adapted the reaction conditions to allow for product formation in as little as 5 min, with yields often >80%.

The Role of Archpriest Eugene Popov in Enhancing of the Anglican-Orthodox Dialog

2020 ◽  
pp. 71-84
Author(s):  
Ярослав Очканов
Keyword(s):  
State Level ◽  
Structural Features ◽  
Russian Orthodox ◽  
Church Community ◽  
Anglican Church ◽  
Current State ◽  
The Church

Статья посвящена исследованию малоизученной стороны деятельности видного русского священнослужителя протоиерея Евгения Попова, бывшего с 1842 по 1875 гг. настоятелем русской посольской церкви в Лондоне. Его служение на Английской земле совпало с углублением диалога между Русской Православной и Англиканской церквами, явившегося следствием религиозных преобразований в Англии в 1830 - 1840-е гг. Отец Евгений в рассматриваемый период фактически стал связующим звеном между русским церковноначалием и англиканами - инициаторами единения двух Церквей. Он проделал огромную работу по популяризации православия в Англии и много сделал для ознакомления русской церковной общественности с вероучением и структурными особенностями англиканства. Материалом для исследования послужили, прежде всего, письма протоиерея Евгения Попова обер-прокурорам Святейшего Синода Н. А. Протасову и А. П. Толстому. Эти документы являются своеобразными отчётами о современном состоянии Англиканской Церкви, о религиозных течениях в ней и усилиях, предпринимаемых определёнными церковными кругами в Англии по сближению с православием. Результаты его деятельности имели важное значение в последующие десятилетия, когда англикано-православный диалог вышел на церковно-государственный уровень. The article is devoted to the insufficiently studied aspects of Russian prominent cleric Archpriest Eugene Popov, rector of Russian Embassy Church in London from 1842 to 1875. His Ministry on the English soil coincided with the deepening of the dialogue between the Russian Orthodox and Anglican Churches, which was the result of religious transformations in England in the 1830s and 1840s. Father Eugene in the period under consideration actually became a connecting link between the Russian Church authorities and the anglicans-initiators of the union of the two Churches. He had done a great job by popularizing Orthodoxy in England and by familiarizing the Russian Church community with the doctrine and structural features of Anglicanism. The study, first of all, is based the letters of Archpriest Yevgeny Popov to the chief prosecutors of the Holy Synod N. A. Protasov and A. P. Tolstoy, which were original reports on the current state of the Anglican Church, it’s religious trends, and the efforts made by certain Church circles in England to get closer to Orthodoxy. The fruits of his activities were important in the following decades, when the Anglican-Orthodox dialogue reached the Church-state level.

THE USE OF THE TRANSLATION METHOD IN MASTERING THE TERMS

2019 ◽  
pp. 87-95
Keyword(s):  
International Relations ◽  
English Language ◽  
Structural Features ◽  
Point Of View ◽  
General Classification ◽  
Optimal Methods ◽  
Foreign Companies ◽  
The Social ◽  
Problems Of Translation

The article is devoted to the role of Tourism terminology in linguistics and the issue of general classification, peculiarities in the expression and translation of terms related to tourism in English into Uzbek and Russian, as well as the choice of the most optimal methods for translating terms in accordance with the requirements of this professional sphere. The terminology of the English language tourism is distinguished by its brightness, versatility. Tourism terms are formed under the influence of a generalized lexical layer of language and perform a specific functional function.Tourism terms are formed through the affixation method (prefixation, suffixation, circumphixation) and get rich through the process.The terminology of English Tourism is distinguished by its content and structural features, forming a part of the language vocabulary from the linguistic point of view. Texts in the field of Tourism take into their composition concepts of Tourism and interpret them in their content. They will be mainly in the form of advertising, as well as enlighten information about a particular region or place, create informational precedents and ensure their manifestation in the social cultural presence. The relevance of the study of the problems of translation of terms in the field of tourism has been investigated, mainly due to the development of international relations, expansion of cooperation between local and foreign companies, as well as the increase in this area of communication.

Microbial Bioconversion: A Regio-specific Method for Novel Drug Design and Toxicological Study of Metabolites

2019 ◽  
Vol 20 (14) ◽  
pp. 1156-1162
Author(s):  
Maria Yousuf ◽  
Waqas Jamil ◽  
Khayala Mammadova
Keyword(s):  
Microbial Transformation ◽  
Specific Method ◽  
Reaction Conditions ◽  
Small Organic Molecules ◽  
Toxicological Studies ◽  
Drug Designing ◽  
Transformation Methods ◽  
Novel Drug

The methods of chemical structural alteration of small organic molecules by using microbes (fungi, bacteria, yeast, etc.) are gaining tremendous attention to obtain structurally novel and therapeutically potential leads. The regiospecific mild environmental friendly reaction conditions with the ability of novel chemical structural modification in compounds categorize this technique; a distinguished and unique way to obtain medicinally important drugs and their in vivo mimic metabolites with costeffective and timely manner. This review article shortly addresses the immense pharmaceutical importance of microbial transformation methods in drug designing and development as well as the role of CYP450 enzymes in fungi to obtain in vivo drug metabolites for toxicological studies.

TBAI Catalyzed Electrochemical C-H Bond Activation of 2-arylated-N-methoxyamides for the Synthesis of Phenanthridinones

Synlett ◽  
2021 ◽  
Author(s):  
Kripa Subramanian ◽  
Subhash L. Yedage ◽  
Kashish Sethi ◽  
Bhalchandra M. Bhanage
Keyword(s):  
Electrochemical Method ◽  
Bond Activation ◽  
Supporting Electrolyte ◽  
Bioactive Compound ◽  
Reaction Conditions ◽  
Redox Catalyst ◽  
Synthetic Utility ◽  
One Step ◽  
Constant Potential

An electrochemical method for the synthesis of phenanthridinones via constant potential electrolysis (CPE) mediated by <i>n</i>-Bu<sub>4</sub>NI (TBAI) has been reported. The protocol is metal and oxidant free and proceeds with 100% current efficiency. Here TBAI plays the dual role of the redox catalyst as well as supporting electrolyte. The intramolecular C-H activation proceeds under mild reaction conditions and short reaction time via electrochemically generated amidyl radicals. The reaction has been scaled up to gram level showing its practicability and the synthetic utility and applicability of the protocol has been demonstrated by the direct one-step synthesis of the bioactive compound Phenaglaydon.

N-Chlorinative Ring Contraction of 1,4-Dimethoxyphthalazines via a Bicyclization/Ring-Opening Mechanism

Synthesis ◽  
2020 ◽  
Author(s):  
Jeong Kyun Im ◽  
Ilju Jeong ◽  
Jun-Ho Choi ◽  
Won-jin Chung ◽  
ByeongDo Yang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Reaction Conditions ◽  
Ring Contraction ◽  
Silyl Group ◽  
Favorskii Rearrangement ◽  
Mechanistic Analysis ◽  
Group A ◽  
Overall Efficiency ◽  
Trichloroisocyanuric Acid

AbstractAn unprecedented N-chlorinative ring contraction of 1,2-diazines was discovered and investigated with an electrophilic chlorinating reagent, trichloroisocyanuric acid (TCICA). Through optimization and mechanistic analysis, the assisting role of n-Bu4NCl as an exogenous nucleophile was identified, and the optimized reaction conditions were applied to a range of 1,4-dimethoxyphthalazine derivatives. Also, an improvement of overall efficiency was demonstrated by the use of a labile O-silyl group. A bicyclization/ring-opening mechanism, inspired by the Favorskii rearrangement, was proposed and supported by the DFT calculations. Furthermore, the efforts on scope expansion as well as the evaluation of other electrophilic promoters revealed that the newly developed ring contraction reactivity is a unique characteristic of 1,4-dimethoxyphthalazine scaffold and TCICA.

Are All Lockdown Teams Created Equally? Work Characteristics and Team Perceived Virtuality

2021 ◽  
pp. 104649642199789
Author(s):  
Patrícia L. Costa ◽  
Lisa Handke ◽  
Thomas A. O’Neill
Keyword(s):  
Virtual Teams ◽  
Organizational Support ◽  
Latent Profile Analysis ◽  
Profile Analysis ◽  
Structural Features ◽  
Pivotal Role ◽  
Work Characteristics ◽  
Team Members ◽  
Latent Profile

Team virtuality has been mostly conceptualized as structural features, such as the percentage of time team members communicate via technology. However, the perception of distance and of information deficits (team perceived virtuality, TPV) may be an indispensable construct to understand virtual teams’ functioning. The lockdowns imposed on most countries due to COVID-19 created virtual teams with high degrees of structural virtuality. With structural virtuality held constant among teams, we explore configurations of work characteristics (autonomy, interdependence, and organizational support) that influence TPV. With a sample of 296 multinational workers, a Latent Profile Analysis identified four distinct profiles of those work characteristics. Those profiles related differently to TPV. Contrary to previous findings, interdependence seems to play an important role in these teams high in structural virtuality when their autonomy is also high, highlighting the pivotal role of frequent interaction among team members, under conditions of high structural virtuality.

Understanding factors controlling depolymerization and polymerization in catalytic degradation of β-ether linked model lignin compounds by versatile peroxidase

2017 ◽  
Vol 19 (9) ◽  
pp. 2145-2154 ◽  
Author(s):  
Jijiao Zeng ◽  
Matthew J. L. Mills ◽  
Blake A. Simmons ◽  
Michael S. Kent ◽  
Kenneth L. Sale
Keyword(s):  
Structural Features ◽  
Catalytic Degradation ◽  
Versatile Peroxidase ◽  
Reaction Conditions ◽  
Linked Model

Insights into reaction conditions and structural features of lignin that facilitate its versatile peroxidase catalyzed depolymerization.

scholarly journals Enzymatic synthesis and phosphorolysis of 4(2)-thioxo- and 6(5)-azapyrimidine nucleosides by E. coli nucleoside phosphorylases

2016 ◽  
Vol 12 ◽  
pp. 2588-2601 ◽  
Author(s):  
Vladimir A Stepchenko ◽  
Anatoly I Miroshnikov ◽  
Frank Seela ◽  
Igor A Mikhailopulo
Keyword(s):  
Purine Nucleoside Phosphorylase ◽  
Reaction Conditions ◽  
E Coli ◽  
No Formation ◽  
Structural Peculiarities ◽  
Substrate Properties ◽  
Nucleoside Phosphorylases ◽  
Derivatives Of

The trans-2-deoxyribosylation of 4-thiouracil (4SUra) and 2-thiouracil (2SUra), as well as 6-azauracil, 6-azathymine and 6-aza-2-thiothymine was studied using dG and E. coli purine nucleoside phosphorylase (PNP) for the in situ generation of 2-deoxy-α-D-ribofuranose-1-phosphate (dRib-1P) followed by its coupling with the bases catalyzed by either E. coli thymidine (TP) or uridine (UP) phosphorylases. 4SUra revealed satisfactory substrate activity for UP and, unexpectedly, complete inertness for TP; no formation of 2’-deoxy-2-thiouridine (2SUd) was observed under analogous reaction conditions in the presence of UP and TP. On the contrary, 2SU, 2SUd, 4STd and 2STd are good substrates for both UP and TP; moreover, 2SU, 4STd and 2’-deoxy-5-azacytidine (Decitabine) are substrates for PNP and the phosphorolysis of the latter is reversible. Condensation of 2SUra and 5-azacytosine with dRib-1P (Ba salt) catalyzed by the accordant UP and PNP in Tris∙HCl buffer gave 2SUd and 2’-deoxy-5-azacytidine in 27% and 15% yields, respectively. 6-Azauracil and 6-azathymine showed good substrate properties for both TP and UP, whereas only TP recognizes 2-thio-6-azathymine as a substrate. 5-Phenyl and 5-tert-butyl derivatives of 6-azauracil and its 2-thioxo derivative were tested as substrates for UP and TP, and only 5-phenyl- and 5-tert-butyl-6-azauracils displayed very low substrate activity. The role of structural peculiarities and electronic properties in the substrate recognition by E. coli nucleoside phosphorylases is discussed.

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