ChemInform Abstract: Combining in situ Generated Chiral Silicon Lewis Acid and Chiral Broensted Acid Catalysts for [3 + 2] Cycloadditions: Cooperative Catalysis as a Convenient Enantioselective Route to Pyrazolidines.

ChemInform ◽  
2013 ◽  
Vol 44 (15) ◽  
pp. no-no
Author(s):  
Olga V. Serdyuk ◽  
Alexandru Zamfir ◽  
Frank Hampel ◽  
Svetlana B. Tsogoeva
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Cooperative Catalysis

Structure modulation in zinc–ditetrazolate coordination polymers by in situ ligand synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88809-88815 ◽  
Author(s):  
Yun-Wu Li ◽  
Hui-Yan Ma ◽  
Su-Na Wang ◽  
Jian Xu ◽  
Da-Cheng Li ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Coordination Polymers ◽  
Cycloaddition Reaction ◽  
Acid Catalysts ◽  
Synthesis System ◽  
Lewis Acid Catalysts ◽  
Structure Modulation ◽  
Ligand Synthesis

Three new coordination polymers have been constructed by an in situ ditetrazolate-ligand synthesis system involving the sharpless [2 + 3] cycloaddition reaction between IPN and NaN3 in the presence of Zn2+ ions as 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>

scholarly journals Novel hydrogen chemisorption properties of amorphous ceramic compounds consisting of p-block elements: exploring Lewis acid-base Al–N pair site formed in-situ within polymer-derived silicon-aluminum-nitrogen-based system

2021 ◽  
Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Active Site ◽  
Hydrogen Chemisorption ◽  
Acid Base ◽  
Polymer Derived Ceramics ◽  
System P ◽  
Ceramic Compounds ◽  
The Relationship

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...

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.

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