scholarly journals A three-component, Zn(OTf)2-mediated entry into trisubstituted 2-aminoimidazoles

2019 ◽  
Vol 15 ◽  
pp. 1061-1064 ◽  
Author(s):  
Alexei Lukin ◽  
Anna Bakholdina ◽  
Anna Kryukova ◽  
Alexander Sapegin ◽  
Mikhail Krasavin
Keyword(s):  
Lewis Acid ◽  
Primary Amine ◽  
Three Component Reaction ◽  
Acid Catalyzed ◽  
In Situ Generation

A three-component reaction involving in situ generation of propargylureas and subsequent Zn(OTf)2-mediated cyclocondensation with a primary amine yielded trisubstituted 2-aminoimidazoles. These findings are in contrast to the previously reported base-promoted unimolecular cyclization of propargylureas (leading to 2-imidazolones) and extend the range of Lewis acid-catalyzed azole syntheses based on N-carbonyl propargylamines.

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>

Lewis acid-catalyzed tandem cyclization of in situ generated o-quinone methides and arylsulfonyl hydrazides for a one-pot entry to 3-sulfonylbenzofurans

2019 ◽  
Vol 6 (24) ◽  
pp. 3929-3933 ◽  
Author(s):  
Fan-Xiao Meng ◽  
Ruo-Nan Wang ◽  
Hong-Li Huang ◽  
Shu-Wen Gong ◽  
Qian-Li Li ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Quinone Methides ◽  
One Pot ◽  
Acid Catalyzed ◽  
Tandem Cyclization ◽  
First Time

Lewis acid-mediated one-pot tandem cyclization of o-QMs with arylsulfonyl hydrazides was described for the first time and the corresponding 3-sulfonylbenzofuran products were obtained in moderate to good yields.

Acid-Catalyzed In Situ Generation of Less Accessible or UnprecedentedN-Boc Imines fromN-Boc Aminals

2013 ◽  
Vol 125 (21) ◽  
pp. 5642-5644 ◽  
Author(s):  
Taichi Kano ◽  
Taiga Yurino ◽  
Daisuke Asakawa ◽  
Keiji Maruoka
Keyword(s):  
Acid Catalyzed ◽  
In Situ Generation

Lewis Acid-Catalyzed Intermolecular Annulation: Three-Component Reaction toward Imidazo[1,2-a]pyridine Thiones

2019 ◽  
Vol 84 (14) ◽  
pp. 9369-9377 ◽  
Author(s):  
Zhengwang Chen ◽  
Pei Liang ◽  
Fan Xu ◽  
Rulin Qiu ◽  
Qi Tan ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Three Component Reaction ◽  
Acid Catalyzed

ChemInform Abstract: Acid-Catalyzed in situ Generation of Less Accessible of Unprecedented N-Boc Imines from N-Boc Aminals.

ChemInform ◽  
2013 ◽  
Vol 44 (40) ◽  
pp. no-no
Author(s):  
Taichi Kano ◽  
Taiga Yurino ◽  
Daisuke Asakawa ◽  
Keiji Maruoka
Keyword(s):  
Acid Catalyzed ◽  
In Situ Generation

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>

Lewis acid-catalyzed in situ transesterification/esterification of tigernut in sub/supercritical ethanol: An optimization study

Fuel ◽  
2019 ◽  
Vol 245 ◽  
pp. 96-104 ◽  
Author(s):  
Ye Tian ◽  
Feng Wang ◽  
Long-Fei Xie ◽  
Yu-Ping Xu ◽  
Pei-Gao Duan
Keyword(s):  
Lewis Acid ◽  
In Situ Transesterification ◽  
Optimization Study ◽  
Acid Catalyzed ◽  
Supercritical Ethanol

Lewis Acid-Catalyzed Nucleophilic Addition of Indoles to in Situ-Generated 2-Amidoallyl Cations

2017 ◽  
Vol 82 (11) ◽  
pp. 5986-5992 ◽  
Author(s):  
Marcel Schlegel ◽  
Christoph Schneider
Keyword(s):  
Lewis Acid ◽  
Nucleophilic Addition ◽  
Acid Catalyzed

Evidences of the in situ generation of highly active Lewis acid species on Zr-SBA-15

2009 ◽  
Vol 371 (1-2) ◽  
pp. 85-91 ◽  
Author(s):  
Maria D. Gracia ◽  
Alina M. Balu ◽  
Juan M. Campelo ◽  
Rafael Luque ◽  
Jose M. Marinas ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Highly Active ◽  
In Situ Generation
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