scholarly journals Quantum chemical calculations of stability constants: study of ligand effects on the relative stability of Pd(II)–peptide complexes

2010 ◽  
Vol 128 (4-6) ◽  
pp. 465-475 ◽  
Author(s):  
Elkin Tílvez ◽  
Natalia Díaz ◽  
M. Isabel Menéndez ◽  
Dimas Suárez ◽  
Ramón López
Keyword(s):  
Quantum Chemical Calculations ◽  
Stability Constants ◽  
Relative Stability ◽  
Quantum Chemical ◽  
Ligand Effects ◽  
Peptide Complexes

scholarly journals Stereoselective Synthesis of Multisubstituted Cyclohexanes by Reaction of Conjugated Enynones with Malononitrile in the Presence of LDA

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5920
Author(s):  
Anastasiya V. Igushkina ◽  
Alexander A. Golovanov ◽  
Irina A. Boyarskaya ◽  
Ilya E. Kolesnikov ◽  
Aleksander V. Vasilyev
Keyword(s):  
Reaction Mechanism ◽  
Quantum Chemical Calculations ◽  
Relative Stability ◽  
Quantum Chemical ◽  
Room Temperature ◽  
Stereoselective Synthesis ◽  
Dft Method ◽  
Lithium Diisopropylamide ◽  
Reaction Conditions

Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile in the presence of lithium diisopropylamide LDA, as a base, in THF at room temperature for 3–7 h resulted in the formation of the product of dimerization, multisubstituted polyfunctional cyclohexanes, 4-aryl-2,6-bis(arylethynyl)-3-(aryloxomethyl)-4-hydroxycyclohexane-1,1-dicarbonitriles, in yields up to 60%. Varying the reaction conditions by decreasing time and temperature and changing the ratio of starting compounds (enynone and malononitrile) allowed isolating some intermediate compounds, which confirmed a plausible reaction mechanism. The relative stability of possible stereoisomers of such cyclohexanes was estimated by quantum chemical calculations (DFT method). The obtained cyclohexanes were found to possess photoluminescent properties.

Quantum-chemical calculations of the relative stability of the keto-enol tautomers of 5-chlorouracyl

2012 ◽  
Vol 86 (7) ◽  
pp. 1104-1108 ◽  
Author(s):  
T. I. Lukmanov ◽  
G. S. Abdrakhimova ◽  
E. M. Khamitov ◽  
S. P. Ivanov
Keyword(s):  
Quantum Chemical Calculations ◽  
Relative Stability ◽  
Quantum Chemical

scholarly journals Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

2013 ◽  
Vol 9 ◽  
pp. 809-817 ◽  
Author(s):  
Sandeep Kumar ◽  
Ramendra Pratap ◽  
Abhinav Kumar ◽  
Brijesh Kumar ◽  
Vishnu K Tandon ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Relative Stability ◽  
Quantum Chemical ◽  
Noncovalent Interactions ◽  
Reaction Conditions ◽  
One Pot ◽  
Supramolecular Architectures ◽  
Novel Approach

A direct one-pot base-induced alkenylation of indolin-2-ones has been developed by using 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles. Different bases such as MeONa, NaH and t-BuONa have been used to optimize the reaction conditions to obtain the desired product. NaH in THF was found to be the most suitable for the alkenylation of indolin-2-ones. Reaction in the presence of other bases led to the formation of 1-aryl-3-methoxy/methylthio-5H-dibenzo[d,f][1,3]diazepin-6(7H)-ones. Quantum chemical calculations have been performed to explain the nature of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others.

Discovery of a Difluoroglycine Synthesis Method through Quantum Chemical Calculations

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda
Keyword(s):  
Quantum Chemical Calculations ◽  
Experimental Verification ◽  
Quantum Chemical ◽  
Synthesis Method ◽  
Target Product ◽  
Systematic Exploration ◽  
Hands On ◽  
Retrosynthetic Analysis ◽  
Synthetic Routes ◽  
Verification Process

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.

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