Superelectrophilic Fe(III)–Ion Pairs as Stronger Lewis Acid Catalysts for (E)-Selective Intermolecular Carbonyl–Olefin Metathesis

2020 ◽  
Vol 22 (8) ◽  
pp. 3155-3160 ◽  
Author(s):  
Haley Albright ◽  
Hannah L. Vonesh ◽  
Corinna S. Schindler
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Ion Pairs ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

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>

Hydrothermal synthesis of Sn-Beta zeolites in F−-free medium

2018 ◽  
Vol 5 (11) ◽  
pp. 2763-2771 ◽  
Author(s):  
Hao Xu ◽  
Xudong Wang ◽  
Peng Ji ◽  
Haihong Wu ◽  
Yejun Guan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lewis Acid ◽  
Crystal Size ◽  
Acid Catalysts ◽  
Free Medium ◽  
Lewis Acid Catalysts ◽  
Structure Directing Agent ◽  
Highly Active ◽  
Beta Zeolites

Sn-Beta zeolites, with high Sn content and smaller crystal size, hydrothermally synthesized in F−-free medium using N-cyclohexyl-N,N-dimethylcyclohexanaminium hydroxide as the structure-directing agent with the assistance of Na+ and seed, are highly active as Lewis acid catalysts.

Assessment of fluoroalkyltin compounds as fluorous Lewis acid catalysts

2003 ◽  
Vol 17 (10) ◽  
pp. 795-799 ◽  
Author(s):  
Yasuo Imakura ◽  
Satoru Nishiguchi ◽  
Akihiro Orita ◽  
Junzo Otera
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

ChemInform Abstract: Calcium-Based Lewis Acid Catalysts

ChemInform ◽  
2013 ◽  
Vol 44 (40) ◽  
pp. no-no
Author(s):  
Jeanne-Marie Begouin ◽  
Meike Niggemann
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

Catalyzed Orientation Reversals in Diels–Alder Reactions

1975 ◽  
Vol 53 (4) ◽  
pp. 616-618 ◽  
Author(s):  
Žarko Stojanac ◽  
Robert A. Dickinson ◽  
Nada Stojanac ◽  
Ronald J. Woznow ◽  
Zdenek Valenta
Keyword(s):  
Lewis Acid ◽  
Diels Alder ◽  
Acid Catalysts ◽  
Acid Salt ◽  
Lewis Acid Catalysts ◽  
Preferential Formation ◽  
Orientation Reversal

Lewis acid catalysts cause an orientation reversal in the Diels–Alder additions of 2,6-di-methyl-1,4-quinone (1) and toluquinone (12) to 1-substituted 1,3-butadienes and to 1,2- and 1,3-dialkyl dienes. These results are explained by the preferential formation of one reactive quinone–Lewis acid salt.

Supported Lewis Acid Catalysts Based on Polyolefin Thermoplastics

1993 ◽  
pp. 87-99 ◽  
Author(s):  
T. C. Chung ◽  
A. Kumar ◽  
F. Chen ◽  
J. Stanat
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts
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