scholarly journals Lewis acid / Base-free Strategy for the Synthesis of 2-Arylthio and Selenyl Benzothiazole / Thiazole and Imidazole

2021 ◽  
Vol 27 (1) ◽  
pp. 17-23
Author(s):  
Guniganti Balakishan ◽  
Gullapalli Kumaraswamy ◽  
Vykunthapu Narayanarao ◽  
Pagilla Shankaraiah
Keyword(s):  
Lewis Acid ◽  
Bond Formation ◽  
Acid Base ◽  
Mechanistic Pathway ◽  
Wide Range ◽  
Acid And Base ◽  
Lewis Acid And Base ◽  
Sulfur Bond

Abstract A Cu(II)-catalyzed Csp2-Se and Csp2-Sulfur bond formation was achieved with moderate to good yields without the aid of Lewis acid and base. The reaction is compatible with a wide range of heterocycles such as benzothiazole, thiazole, and imidazole. Also, this typical protocol is found to be active in thio-selenation via S-H activation. Additionally, we proposed a plausible mechanistic pathway involving Cu(III) putative intermediate.

scholarly journals On the concept of frustrated Lewis pairs

2017 ◽  
Vol 375 (2101) ◽  
pp. 20170004 ◽  
Author(s):  
Frédéric-Georges Fontaine ◽  
Douglas W. Stephan
Keyword(s):  
Lewis Acid ◽  
Bond Formation ◽  
Frustrated Lewis Pairs ◽  
Metal Chemistry ◽  
Frustrated Lewis Pair ◽  
Acid And Base ◽  
Definition Of ◽  
Lewis Acid And Base ◽  
Pair Work ◽  
Lewis Pairs

In this concept article, we consider the notion of ‘frustrated Lewis pairs’ (FLPs). While the original use of the term referred to steric inhibition of dative bond formation in a Lewis pair, work in the intervening decade demonstrates the limitation of this simplistic view. Analogies to known transition metal chemistry and the applications in other areas of chemistry are considered. In the light of these findings, we present reflections on the criteria for a definition of the term ‘frustrated Lewis pair’. Segregation of the Lewis acid and base and the kinetic nature of FLP reactivity are discussed. We are led to the conclusion that, while an all-inclusive definition of FLP is challenging, the notion of ‘FLP chemistry’ is more readily recognized. This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.

Theoretical Evaluation of the Efficiency of Novel Frustrated Lewis Pairs in the cis-Hydrogenation Reaction of Dimethylacetylene

2017 ◽  
Vol 42 (4) ◽  
pp. 372-383 ◽  
Author(s):  
Nazanin Noroozi-Shad ◽  
Mostafa Gholizadeh ◽  
Mohammad Izadyar ◽  
Hossein Eshghi
Keyword(s):  
Lewis Acid ◽  
Hydrogenation Reaction ◽  
Lewis Acidity ◽  
Small Molecule Activation ◽  
Frustrated Lewis Pairs ◽  
Theoretical Evaluation ◽  
Wide Range ◽  
Acid And Base ◽  
Lewis Acid And Base ◽  
Lewis Pairs

Frustrated Lewis pairs (FLPs) are the combination of Lewis acid and base motifs where steric hindrance prevents strong adduct formation. Accordingly, the ability of FLPs in small molecule activation and their capability in hydrogen cleavage led to their use in the hydrogenation of a wide range of unsaturated substrates. Here, we investigated theoretically the ability of three intramolecular phosphorus/boron FLPs as bifunctional catalysts in the metal-free hydrogenation of dimethylacetylene to cis-alkene. The mechanism of this hydrogenation reaction, based on the boron acceptor [including –OR substituents (B(OR)2), where R is an aliphatic or aromatic branch] and phosphorus donor, has been explored. Based on the results obtained, it was confirmed that the H2 splitting reaction and the formation of the phosphonium–borohydride motifs for these FLPs are endothermic. It has been shown that these FLPs have a moderate ability in H–H bond splitting. Also, the capability of the boron atom in FLPs on the hydrogenation reaction was investigated. The reduction steps of the mechanism showed an exothermic nature. This result revealed that the presence of the boron as a Lewis acid, with a very limited Lewis acidity, improves the catalytic hydrogenation reaction significantly. Finally, it was confirmed that the proposed FLPs in the cis-hydrogenation of alkynes will be effective.

Combined theoretical and experimental study on alcoholysis of amides on CeO2 surface: A catalytic interplay between Lewis acid and base sites

2018 ◽  
Vol 303 ◽  
pp. 256-262 ◽  
Author(s):  
Takashi Kamachi ◽  
S.M.A. Hakim Siddiki ◽  
Yoshitsugu Morita ◽  
Md. Nurnobi Rashed ◽  
Kenichi Kon ◽  
...  
Keyword(s):  
Experimental Study ◽  
Lewis Acid ◽  
Acid And Base ◽  
Lewis Acid And Base

Role of the Surface Lewis Acid and Base Sites in the Adsorption of CO2 on Titania Nanotubes and Platinized Titania Nanotubes: An in Situ FT-IR Study

2013 ◽  
Vol 117 (24) ◽  
pp. 12661-12678 ◽  
Author(s):  
Kaustava Bhattacharyya ◽  
Alon Danon ◽  
Baiju K.Vijayan ◽  
Kimberly A. Gray ◽  
Peter C. Stair ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Titania Nanotubes ◽  
Acid And Base ◽  
Ft Ir ◽  
Ir Study ◽  
Adsorption Of Co2 ◽  
Lewis Acid And Base

scholarly journals Ruthenium catalysis in organic synthesis

2002 ◽  
Vol 74 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Shun-Ichi Murahashi ◽  
Hikaru Takaya ◽  
Takeshi Naota
Keyword(s):  
Organic Synthesis ◽  
Lewis Acid ◽  
Catalytic Reactions ◽  
Biologically Active ◽  
Hydride Complexes ◽  
Base Catalysts ◽  
Acid And Base ◽  
Ruthenium Catalysis ◽  
Lewis Acid And Base ◽  
Neutral Conditions

Ruthenium, rhodium, iridium, and rhenium hydride complexes are highly useful redox Lewis acid and base catalysts. Various substrates bearing hetero atoms are activated by these catalysts and undergo reactions with either nucleophiles or electrophiles under neutral conditions. These types of catalytic reactions are described together with their application to the preparation of various biologically active compounds.

ChemInform Abstract: ACID AZIDES- PART V - LEWIS ACID- AND BASE-CATALYZED DECOMPOSITIONS OF AZIDES

1977 ◽  
Vol 8 (37) ◽  
pp. no-no
Author(s):  
A. F. FAHMY ◽  
G. HOSNI ◽  
H. ABDEL FADEEL
Keyword(s):  
Lewis Acid ◽  
Acid And Base ◽  
Lewis Acid And Base
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