Conformational Analysis and Rotational Barriers of Alkyl- and Phenyl-Substituted Urea Derivatives

2005 ◽  
Vol 109 (5) ◽  
pp. 832-842 ◽  
Author(s):  
Vyacheslav S. Bryantsev ◽  
Timothy K. Firman ◽  
Benjamin P. Hay
Keyword(s):  
Conformational Analysis ◽  
Urea Derivatives ◽  
Rotational Barriers ◽  
Substituted Urea

Catalyst-Control over Sixfold Stereogenicity

2020 ◽  
Author(s):  
Xingxing Wu ◽  
Reto M. Witzig ◽  
Rodolphe Beaud ◽  
Christian Fischer ◽  
Daniel Häussinger ◽  
...  
Keyword(s):  
Conformational Analysis ◽  
Higher Order ◽  
Binary Codes ◽  
Rotational Barriers ◽  
Molecular Architectures

Governing higher-order stereogenicity is a long-standing goal in stereoselective catalysis, because it allows to achieve selectivity for more than a twofold number of stereoisomers per stereogenic unit. Current methods warrant control over the power of two stereoisomers and the configurations are routinely assigned using the descriptors ( R ) and ( S ), or related binary codes. In contrast, conformational analysis ranges beyond this dualistic treatment of stereoisomerism, which constitutes an unmet challenge for catalyst stereocontrolled processes. Herein, we now report that sixfold stereogenicity can be governed by stereoselective catalysis. By controlling a configurationally stable stereogenic axis with six large rotational barriers, a catalytic [2+2+2]-cyclotrimerization selectively governs the formation of one out of six stereoisomers with up to 0:0:2:98:0:0 stereocontrol. The underpinnings of conformational analysis and stereoselective catalysis are thereby conceptually reunited. Novel molecular architectures featuring distinct chemical topologies and unexplored chemical designs are anticipated from catalystcontrol over higher-order stereogenicities

scholarly journals Microwave Assisted Synthesis and Antimicrobial Activity of 1-(2-Chloropyridin-3-yl)-3-substituted Urea Derivatives

2018 ◽  
Vol 31 (1) ◽  
pp. 41-44
Author(s):  
Vijay Kumar Pujari ◽  
Srilalitha Vinnakota ◽  
Ramana Kumar Kakarla ◽  
Sridhar Marojua
Keyword(s):  
Antimicrobial Activity ◽  
Microwave Assisted Synthesis ◽  
Urea Derivatives ◽  
Microwave Assisted ◽  
Substituted Urea

ChemInform Abstract: Alkanediyl Bridged Calix(4)arenes: Synthesis, Conformational Analysis, and Rotational Barriers.

ChemInform ◽  
2010 ◽  
Vol 28 (16) ◽  
pp. no-no
Author(s):  
S. E. BIALI ◽  
V. BOEHMER ◽  
S. COHEN ◽  
G. FERGUSON ◽  
C. GRUETTNER ◽  
...  
Keyword(s):  
Conformational Analysis ◽  
Rotational Barriers

scholarly journals Design, synthesis, and anti-HIV-1 activity of 1-aromatic methyl-substituted 3-(3,5-dimethylbenzyl)uracil and N-3,5-dimethylbenzyl-substituted urea derivatives

2015 ◽  
Vol 24 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Norikazu Sakakibara ◽  
Masanori Baba ◽  
Mika Okamoto ◽  
Masaaki Toyama ◽  
Yosuke Demizu ◽  
...  
Keyword(s):  
Urea Derivatives ◽  
Design Synthesis ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Substituted Urea

scholarly journals The Modification of Polyurethane Foams Using New Boroorganic Polyols: Obtaining of Polyols with the Use of Hydroxypropyl Urea Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Iwona Zarzyka
Keyword(s):  
Physical Properties ◽  
Boric Acid ◽  
Propylene Carbonate ◽  
Spectral Characteristics ◽  
Polyurethane Foams ◽  
Thermal Stabilities ◽  
Urea Derivatives ◽  
Methods Of Synthesis ◽  
Derivatives Of ◽  
Substituted Urea

Methods of synthesis of new prospective polyol components for obtaining of polyurethane foams of reduced combustibility using eco-friendly substrates have been presented. With this end in view, N,N′-bis(2-hydroxypropyl)urea was esterified with boric acid and next the hydrogenborate obtained was hydroxyalkylated by the excess of propylene carbonate. The influence of the way of esterification on the hydroxypropyl derivatives of borate substituted urea properties has been investigated. Esterification was run in the presence and in the absence of solvent. According to instrumental analysis, the characteristic of hydrogenborates obtained in both methods was found to be similar. The hydroxypropyl derivatives of borate substituted urea show similar spectral characteristics and thermal stabilities and differ slightly in molar masses, by-product contents, and physical properties, particularly viscosities. The properties of these derivatives were assessed paying special attention to their application as the polyol components of polyurethane foams. Hydroxypropyl urea derivatives, modified by boric acid, show changes in physical properties with temperature, similarly to typical polyols used for obtaining of polyurethane foams.

Recent advances in Synthesis and Biological Applications of Substituted Ureas

2021 ◽  
Vol 25 ◽  
Author(s):  
Bharatkumar M. Sapkal ◽  
Shamrao T. Disale ◽  
Raghunath B. Toche ◽  
Dhananjay H. More
Keyword(s):  
Protease Inhibitor ◽  
Biological Activities ◽  
Biological Behavior ◽  
Synthetic Approach ◽  
Biological Applications ◽  
Urea Derivatives ◽  
Heterocyclic Molecules ◽  
Hiv 1 ◽  
Antiproliferative Activities ◽  
Substituted Urea

: In the last few decades, substituted urea derivatives have got significant importance due to their wide applications in pharmaceutical, polymer, dyes, and agriculture industries. Urea derivatives are the key starting material for the synthesis of novel bioactive heterocyclic molecules. Substituted urea derivatives are known to possess a wide array of biological activities such as herbicidal, antimicrobial, antimalarial, antivirus, anticancer, antioxidants, antiproliferative, antiatherosclerotic, anti-inflammatory, antibiotic, sedatives, anticonvulsants and acting as HIV-1 protease inhibitor. Herein, the synthetic approach and its herbicidal, anticonvulsant, antimicrobial, and antiproliferative activities are reviewed. This review summarizes the current updates regarding the syntheses and biological behavior of substituted urea.

Synthesis of some N-alkyl substituted urea derivatives as antibacterial and antifungal agents

2010 ◽  
Vol 45 (7) ◽  
pp. 3207-3212 ◽  
Author(s):  
Qing-Zhong Zheng ◽  
Kui Cheng ◽  
Xiao-Min Zhang ◽  
Kai Liu ◽  
Qing-Cai Jiao ◽  
...  
Keyword(s):  
Antifungal Agents ◽  
Urea Derivatives ◽  
Antibacterial And Antifungal ◽  
Substituted Urea

scholarly journals Synthesis and Pharmacological Evaluation of Novel 1-(1,4-Alkylaryldisubstituted-4,5-dihydro-1H-imidazo)-3-substituted Urea Derivatives

Molecules ◽  
2016 ◽  
Vol 21 (5) ◽  
pp. 582 ◽  
Author(s):  
Elżbieta Szacoń ◽  
Marzena Rządkowska ◽  
Agnieszka Kaczor ◽  
Ewa Kędzierska ◽  
Jolanta Orzelska-Górka ◽  
...  
Keyword(s):  
Urea Derivatives ◽  
Pharmacological Evaluation ◽  
Substituted Urea
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