Lewis Acid Catalyzed Site-Selective Cycloadditions of 2,6-Diazasemibullvalenes with Isocyanides, Azides, and Diazo Compounds for the Synthesis of Diaza- and Triazabrexadiene Derivatives

2013 ◽  
Vol 125 (12) ◽  
pp. 3569-3573 ◽  
Author(s):  
Shaoguang Zhang ◽  
Wen-Xiong Zhang ◽  
Zhenfeng Xi
Keyword(s):  
Lewis Acid ◽  
Diazo Compounds ◽  
Acid Catalyzed ◽  
Site Selective

scholarly journals Synergistic Brønsted/Lewis Acid Catalyzed Aromatic Alkylation with Unactivated Tertiary Alcohols or Di-tert-Butylperoxide to Synthesize Quaternary Carbon Centers

2021 ◽  
Author(s):  
Aaron Pan ◽  
Maja Chojnacka ◽  
Robert Crowley ◽  
Lucas Gottemann ◽  
Brandon Haines ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Alkylating Agents ◽  
Environmentally Benign ◽  
Quaternary Carbon ◽  
Tertiary Alcohols ◽  
Carbon Centers ◽  
Acid Catalyzed ◽  
Site Selective

Dual Brønsted/Lewis acid catalysis involving environmentally benign, readily accessible protic acid and iron promotes site-selective tert-butylation of electron-rich arenes using di-tert-butylperoxide. This transformation inspired the development of a synergistic Brønsted/Lewis acid catalyzed aromatic alkylation that fills a gap in the Friedel–Crafts reaction literature by employing unactivated tertiary alcohols as alkylating agents, leading to new quaternary carbon centers. Corroborated by DFT calculations, the Lewis acid serves a role in enhancing the acidity of the Brønsted acid. The use of non-allylic, non-benzylic, and non-propargylic tertiary alcohols represents an underexplored area in Friedel–Crafts reactivity.

Cu(i)-carbenoid- and Ag(i)-Lewis acid-catalyzed asymmetric intermolecular insertion of α-diazo compounds into N–H bonds

2004 ◽  
Vol 2 (20) ◽  
pp. 3044-3049 ◽  
Author(s):  
Stephan Bachmann ◽  
Doris Fielenbach ◽  
Karl Anker Jørgensen
Keyword(s):  
Lewis Acid ◽  
Diazo Compounds ◽  
Acid Catalyzed

Cu(I)-Carbenoid- and Ag(I)-Lewis Acid-Catalyzed Asymmetric Intermolecular Insertion of ?-Diazo Compounds into N?H Bonds.

ChemInform ◽  
2005 ◽  
Vol 36 (10) ◽  
Author(s):  
Stephan Bachmann ◽  
Doris Fielenbach ◽  
Karl Anker Joergensen
Keyword(s):  
Lewis Acid ◽  
Diazo Compounds ◽  
Acid Catalyzed

Lewis acid-catalyzed reactions of N-allylanilines with diazo compounds involving aza-Claisen rearrangement

2015 ◽  
Vol 25 (6) ◽  
pp. 438-439 ◽  
Author(s):  
Alexander G. Badamshin ◽  
Leonid V. Spirikhin ◽  
Rinat F. Salikov ◽  
Vladimir A. Dokichev ◽  
Yury V. Tomilov
Keyword(s):  
Lewis Acid ◽  
Claisen Rearrangement ◽  
Diazo Compounds ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

ChemInform Abstract: Lewis Acid-Catalyzed Reactions of N-Allylanilines with Diazo Compounds Involving Aza-Claisen Rearrangement.

ChemInform ◽  
2016 ◽  
Vol 47 (19) ◽  
Author(s):  
Alexander G. Badamshin ◽  
Leonid V. Spirikhin ◽  
Rinat F. Salikov ◽  
Vladimir A. Dokichev ◽  
Yury V. Tomilov
Keyword(s):  
Lewis Acid ◽  
Claisen Rearrangement ◽  
Diazo Compounds ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

scholarly journals Comparison of Corn Stover Pretreatments with Lewis Acid Catalyzed Choline Chloride, Glycerol and Choline Chloride-Glycerol Deep Eutectic Solvent

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1170
Author(s):  
Yuan Zhu ◽  
Benkun Qi ◽  
Xinquan Liang ◽  
Jianquan Luo ◽  
Yinhua Wan
Keyword(s):  
Corn Stover ◽  
Lewis Acid ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Enzymatic Saccharification ◽  
Glycerol Solution ◽  
Cellulose Conversion ◽  
Biomass Processing ◽  
Acid Catalyzed ◽  
Highly Correlated

Herein, corn stover (CS) was pretreated by less corrosive lewis acid FeCl3 acidified solutions of neat and aqueous deep eutectic solvent (DES), aqueous ChCl and glycerol at 120 °C for 4 h with single FeCl3 pretreatment as control. It was unexpected that acidified solutions of both ChCl and glycerol were found to be more efficient at removing lignin and xylan, leading to higher enzymatic digestibility of pretreated CS than acidified DES. Comparatively, acidified ChCl solution exhibited better pretreatment performance than acidified glycerol solution. In addition, 20 wt% water in DES dramatically reduced the capability of DES for delignification and xylan removal and subsequent enzymatic cellulose saccharification of pretreated CS. Correlation analysis showed that enzymatic saccharification of pretreated CS was highly correlated to delignification and cellulose crystallinity, but lowly correlated to xylan removal. Recyclability experiments of different acidified pretreatment solutions showed progressive decrease in the pretreatment performance with increasing recycling runs. After four cycles, the smallest decrease in enzymatic cellulose conversion (22.07%) was observed from acidified neat DES pretreatment, while the largest decrease (43.80%) was from acidified ChCl pretreatment. Those findings would provide useful information for biomass processing with ChCl, glycerol and ChCl-glycerol DES.

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