scholarly journals A synergistic LUMO lowering strategy using Lewis acid catalysis in water to enable photoredox catalytic, functionalizing C–C cross-coupling of styrenes

2018 ◽  
Vol 9 (35) ◽  
pp. 7096-7103 ◽  
Author(s):  
Elisabeth Speckmeier ◽  
Patrick J. W. Fuchs ◽  
Kirsten Zeitler
Keyword(s):  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Lewis Acids ◽  
Acid Catalysis ◽  
Cross Coupling ◽  
Bond Breaking ◽  
Lewis Acid Catalysis

Synergistic LUMO activation by water and lanthanide Lewis acids allows for photocatalyzed C–O bond breaking cross coupling of α-acetoxy carbonyl compounds with styrenes.

scholarly journals Green Lewis acid catalysis in organic synthesis

2000 ◽  
Vol 72 (7) ◽  
pp. 1373-1380 ◽  
Author(s):  
Shū Kobayashi ◽  
Kei Manabe
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Acid Catalysis ◽  
Aqueous Media ◽  
Earth Metal ◽  
Metal Salts ◽  
Lewis Acid Catalysis ◽  
Bond Forming ◽  
Combined Catalysts ◽  
Metal Triflates

New types of Lewis acids as water-stable catalysts have been developed. Metal salts such as rare earth metal triflates can be used in carbon_carbon bond-forming reactions in aqueous media. These salts can be recovered after the reactions and reused. Furthermore, Lewis acid_surfactant-combined catalysts, which can be used for reactions in water without using any organic solvents, have been also developed. Finally, Lewis acid catalysis in supercritical carbon dioxide has been successfully performed. These investigations will contribute to development of environmentally friendly Lewis acid catalysis.

A Synergistic LUMO Lowering Strategy Using Lewis Acid Catalysis in Water to Enable Photoredox Catalytic, Functionalizing C-C Cross-Coupling of Styrenes

2018 ◽  
Author(s):  
Elisabeth Speckmeier ◽  
Patrick J. W. Fuchs ◽  
Kirsten Zeitler
Keyword(s):  
Cyclic Voltammetry ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Alkyl Radical ◽  
Acid Catalysis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Catalytic Activation ◽  
Type Transformation ◽  
Acetophenone Derivatives

Easy available alpha-carbonyl acetates serve as convenient alkyl radical source for an efficient, photocatalytic crosscoupling with a great variety of styrenes. Activation of electronically different alpha-acetylated acetophenone derivatives could be effected via LUMO lowering catalysis using a superior, synergistic combination of water and (water-compatible) Lewis acids. Deliberate application of <i>fac</i>-Ir(ppy)<sub>3</sub> as photocatalyst to enforce an oxidative quenching cycle is crucial to the success of this (umpolung type) transformation. Mechanistic particulars of this dual catalytic coupling reaction have been studied in detail using both Stern-Volmer and cyclic voltammetry experiments. As demonstrated in more than 30 examples, our waterassisted<br>LA/photoredox catalytic activation strategy allows for excess-free, equimolar radical cross-coupling and subsequent formal Markovnikov hydroxylation to versatile 1,4-difunctionalized products in good to excellent yields.

A Synergistic LUMO Lowering Strategy Using Lewis Acid Catalysis in Water to Enable Photoredox Catalytic, Functionalizing C-C Cross-Coupling of Styrenes

2018 ◽  
Author(s):  
Elisabeth Speckmeier ◽  
Patrick J. W. Fuchs ◽  
Kirsten Zeitler
Keyword(s):  
Cyclic Voltammetry ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Alkyl Radical ◽  
Acid Catalysis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Catalytic Activation ◽  
Type Transformation ◽  
Acetophenone Derivatives

Easy available alpha-carbonyl acetates serve as convenient alkyl radical source for an efficient, photocatalytic crosscoupling with a great variety of styrenes. Activation of electronically different alpha-acetylated acetophenone derivatives could be effected via LUMO lowering catalysis using a superior, synergistic combination of water and (water-compatible) Lewis acids. Deliberate application of <i>fac</i>-Ir(ppy)<sub>3</sub> as photocatalyst to enforce an oxidative quenching cycle is crucial to the success of this (umpolung type) transformation. Mechanistic particulars of this dual catalytic coupling reaction have been studied in detail using both Stern-Volmer and cyclic voltammetry experiments. As demonstrated in more than 30 examples, our waterassisted<br>LA/photoredox catalytic activation strategy allows for excess-free, equimolar radical cross-coupling and subsequent formal Markovnikov hydroxylation to versatile 1,4-difunctionalized products in good to excellent yields.

scholarly journals Boron-Based Lewis Acid Catalysis: Challenges and Perspectives

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Valeria Nori ◽  
Fabio Pesciaioli ◽  
Arianna Sinibaldi ◽  
Giuliana Giorgianni ◽  
Armando Carlone
Keyword(s):  
Organic Synthesis ◽  
Lewis Acid ◽  
Gold Standard ◽  
Lewis Acids ◽  
Acid Catalysis ◽  
Acid Catalysts ◽  
Chemical Transformations ◽  
Lewis Acid Catalysis ◽  
Lewis Acid Catalysts ◽  
Better Than

In the last two decades, boron-based catalysis has been gaining increasing traction in the field of organic synthesis. The use of halogenated triarylboranes as main group Lewis acid catalysts is an attractive strategy. It has been applied in a growing number of transformations over the years, where they may perform comparably or even better than the gold standard catalysts. This review discusses methods of borane synthesis and cutting-edge boron-based Lewis acid catalysis, focusing especially on tris(pentafluorophenyl)-borane [B(C6F5)3], and other halogenated triarylboranes, highlighting how boron Lewis acids employed as catalysts can unlock a plethora of unprecedented chemical transformations or improve the efficiency of existing reactions.

Lewis Acid-Promoted Suzuki Reaction using Palladium Chloride Anchored on a Polymer as a Catalyst

2008 ◽  
Vol 61 (8) ◽  
pp. 610 ◽  
Author(s):  
Guozhi Fan ◽  
Hanjun Zhang ◽  
Siqing Cheng ◽  
Zhandong Ren ◽  
Zhijun Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Heterogeneous Catalysts ◽  
Suzuki Reaction ◽  
Cross Coupling ◽  
Palladium Chloride ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Recoverable Catalyst

Palladium chloride anchored on polystyrene modified by 5-amino-1,10-phenanthroline was prepared and used as an efficient recoverable catalyst for Suzuki cross-coupling reactions. The heterogeneous catalysts can be easily separated from the reaction mixture and reused for five cycles without significant Pd leaching and loss of catalytic activity. Rate enhancement in the Suzuki reaction by Lewis acids was also studied.

Chiral Lewis Acid Catalysis in Nitrile Oxide Cycloadditions

2004 ◽  
Vol 126 (17) ◽  
pp. 5366-5367 ◽  
Author(s):  
Mukund P. Sibi ◽  
Kennosuke Itoh ◽  
Craig P. Jasperse
Keyword(s):  
Lewis Acid ◽  
Acid Catalysis ◽  
Nitrile Oxide ◽  
Lewis Acid Catalysis ◽  
Chiral Lewis Acid

Ether Synthesis through Reductive Cross-Coupling of Ketones with Alcohols Using Me2SiHCl as both Reductant and Lewis Acid

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2425-2428 ◽  
Author(s):  
Bill Morandi ◽  
Yong Lee
Keyword(s):  
Functional Groups ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Cross Coupling ◽  
Wide Range ◽  
Direct Cross ◽  
Sterically Hindered ◽  
Polar Functional Groups ◽  
Ether Synthesis ◽  
Dialkyl Ethers

We report that a Lewis acidic silane, Me2SiHCl, can mediate the direct cross-coupling of a wide range of carbonyl compounds with alcohols to form dialkyl ethers. The reaction is operationally simple, tolerates a range of polar functional groups, can be utilized to make sterically hindered ethers, and is extendable to sulfur and nitrogen nucleo­philes.

Lewis Acid Catalysis with Cationic Dinuclear Gold(II,II) and Gold(III,III) Phosphorus Ylide Complexes

2016 ◽  
Vol 35 (17) ◽  
pp. 2830-2835 ◽  
Author(s):  
Benjamin R. Reiner ◽  
Mark W. Bezpalko ◽  
Bruce M. Foxman ◽  
Casey R. Wade
Keyword(s):  
Lewis Acid ◽  
Acid Catalysis ◽  
Lewis Acid Catalysis ◽  
Phosphorus Ylide ◽  
Ylide Complexes
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