Theoretical Confirmation of the Reaction Mechanism Leading to Regioselective Formation of Thiazolidin-4-one from Bromoacetic Acid Derivatives

2007 ◽  
Vol 72 (10) ◽  
pp. 1435-1445 ◽  
Author(s):  
Ladislav Janovec ◽  
Stanislav Böhm ◽  
Ivan Danihel ◽  
Ján Imrich ◽  
Pavol Kristian ◽  
...  

A regioselective synthesis of 3-alkyl-2-[(anthracen-9-yl)imino]thiazolidin-4-ones 2a-2e and 2-(alkylimino)-3-(anthracen-9-yl)thiazolidin-4-ones 3a-3e from appropriate thioureas using methyl bromoacetate or bromoacetyl bromide, respectively, has been rationalized by DFT calculations of model thiourea and its phenyl derivative. The proposed mechanism indicates that the regioselective formation of the target thiazolidinones is a consequence of a different reactivity of the reagents and a varying stability of the intermediates, 1-alkyl-3-(anthracen-9-yl)-2-[(methoxycarbonyl)methyl]isothioureas 4a-4e and 1-alkyl-3-(anthracen-9-yl)-2-(bromoacetyl)isothioureas 6a-6e.

2019 ◽  
Author(s):  
Clare Bakewell ◽  
Martí Garçon ◽  
Richard Y Kong ◽  
Louisa O'Hare ◽  
Andrew J. P. White ◽  
...  

The reactions of an aluminium(I) reagent with a series of 1,2-, 1,3- and 1,5-dienes are reported. In the case of 1,3-dienes the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene containing products. This mechanism has been interrogated by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4+1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4+1) cycloaddition includes dienes that are either in part, or entirely, contained within aromatic rings. In these cases, reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2- or 1,5-dienes complementary reactivity is observed; the orthogonal nature of the C=C π-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavour a (4+1) cycloaddition. Rather, reaction pathways are determined by an initial (2+1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further C=C π-bond leading to complex organometallic products that incorporate fused hydrocarbon rings.


Author(s):  
Reynier Suardíaz ◽  
Emily Lythell ◽  
Philip Hinchliffe ◽  
Marc van der Kamp ◽  
James Spencer ◽  
...  

Elucidation of the catalytic reaction mechanism of MCR-1 enzyme, responsible for the antimicrobial resistance to colistin, using DFT calculations on cluster models.


2021 ◽  
Author(s):  
Fabian A. Watt ◽  
Lukas Burkhardt ◽  
Roland Schoch ◽  
Stefan Mitzinger ◽  
Matthias Bauer ◽  
...  

We present the unprecedented <i>η</i>3-coordination of the 2-phosphaethynthiolate anion in the complex (PN)<sub>2</sub>La(SCP) (<b>2</b>) [PN = N-(2-(diisopropylphosphanyl)-4-methylphenyl)-2,4,6-trimethylanilide)]. Structural comparison with dinuclear thiocyanate bridged (PN)<sub>2</sub>La(<i>μ</i>-1,3-SCN)<sub>2</sub>La(PN)<sub>2</sub> (<b>3</b>) and azide bridged (PN)<sub>2</sub>La(<i>μ</i>-1,3-N3)<sub>2</sub>La(PN)<sub>2</sub> (<b>4</b>) complexes indicates that the [SCP]<sup>–</sup> coordination mode is mainly governed by electronic, rather than steric factors. Quantum mechanical investigations reveal large contributions of the antibonding π-orbital of the [SCP]<sup>–</sup> ligand to the LUMO of complex <b>2</b>, rendering it the ideal precursor for the first functionalization of the [SCP]<sup>–</sup> anion. Complex <b>2</b> was therefore reacted with CAACs which induced a selective rearrangement of the [SCP]<sup>–</sup> ligand to form the first CAAC stabilized group 15 – group 16 fulminate-type complexes (PN)<sub>2</sub>La{SPC(<sup>R</sup>CAAC)} (<b>5a,b</b>) (R = Ad, Me). A detailed reaction mechanism for the SCP to SPC isomerization is proposed based on DFT calculations.


2015 ◽  
Vol 17 (17) ◽  
pp. 11499-11508 ◽  
Author(s):  
Shu-Juan Lin ◽  
Jing Cheng ◽  
Chang-Fu Zhang ◽  
Bin Wang ◽  
Yong-Fan Zhang ◽  
...  

DFT calculations were carried out to study the reaction mechanism for tungsten oxide clusters with CO.


2019 ◽  
Vol 21 (31) ◽  
pp. 17221-17231 ◽  
Author(s):  
Vicent S. Safont ◽  
Iván Sorribes ◽  
Juan Andrés ◽  
Rosa Llusar ◽  
Mónica Oliva ◽  
...  

Transfer hydrogenation cluster catalysis operates through a panoply of cycles, according to DFT calculations, affording a highly efficient catalyst.


2018 ◽  
Vol 20 (36) ◽  
pp. 23311-23319 ◽  
Author(s):  
Po-Yu Yang ◽  
Hsing-Yin Chen ◽  
Shin-Pon Ju ◽  
Chia-Lin Chang ◽  
Gao-Shee Leu ◽  
...  

The detailed reaction mechanism of naphthalene catalytic polymerization by HF/BF3 has been investigated by DFT calculations and the directionality of the naphthalene-derived mesophase molecule has been explained.


2019 ◽  
Vol 43 (48) ◽  
pp. 19308-19317 ◽  
Author(s):  
Zhao Liang ◽  
Chao Liu ◽  
Mingwei Chen ◽  
Xiaopeng Qi ◽  
Pramod Kumar U. ◽  
...  

DFT calculations confirmed that the P–N coupled site changed the ORR pathway and improved the catalytic activity compared with single doping.


2020 ◽  
Vol 92 (1) ◽  
pp. 151-166 ◽  
Author(s):  
Luís M. T. Frija ◽  
Bruno G. M. Rocha ◽  
Maxim L. Kuznetsov ◽  
Lília I. L. Cabral ◽  
M. Lurdes S. Cristiano ◽  
...  

AbstractA new (tetrazole-saccharin)nickel complex is shown to be a valuable catalyst for the hydrosilative reduction of aldehydes under microwave radiation at low temperatures. With typical 1 mol% content of the catalyst (microwave power range of 5–15 W) most reactions are complete within 30 min. The Ni(II)-catalyzed reduction of aldehydes, with a useful scope, was established for the first time by using this catalyst, and is competitive with the most effective transition-metal catalysts known for such transformation. The catalyst reveals tolerance to different functional groups, is air and moisture stable, and is readily prepared in straightforward synthetic steps. Supported by experimental data and DFT calculations, a plausible reaction mechanism involving the new catalytic system is outlined.


1999 ◽  
Vol 64 (26) ◽  
pp. 9493-9498 ◽  
Author(s):  
Angel Alberola ◽  
Luis A. Calvo ◽  
Alfonso González Ortega ◽  
M. Carmen Sañudo Ruíz ◽  
Pedro Yustos ◽  
...  

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