Air- and water-stable Lewis acids: synthesis and reactivity of P-trifluoromethyl electrophilic phosphonium cations

2018 ◽  
Vol 54 (6) ◽  
pp. 662-665 ◽  
Author(s):  
V. Fasano ◽  
J. H. W. LaFortune ◽  
J. M. Bayne ◽  
M. J. Ingleson ◽  
D. W. Stephan
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Acid Catalysts ◽  
Bronsted Acid ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Brönsted Acid ◽  
And Function ◽  
Water Alcohol ◽  
Phosphonium Cations

Electrophilic phosphonium cations (EPCs) containing a –CF3 group are stable to air, water, alcohol and strong Brønsted acid and function as Lewis acid catalysts without requiring anhydrous reaction conditions.

Bidentate Lewis acid catalysts in asymmetric synthesis

2002 ◽  
Vol 74 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Keiji Maruoka
Keyword(s):  
Asymmetric Synthesis ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Asymmetric Induction ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
High Chemical ◽  
Bidentate Lewis Acids

The chemistry of bidentate Lewis acids belongs to an unexplored field of science, and so far has been only poorly studied. This paper illustrates the design of several bidentate Al and Ti Lewis acids, and their successful application to selective organic synthesis, particularly to asymmetric synthesis. For example, a new, chiral bidentate Ti(IV) complex is successfully designed by adding commercially available Ti(OPri)4 and (S)-binaphthol sequentially to 2,2'-bis(tritylamino)-4,4'-dichlorobenzophenone in CH2Cl2, and can be utilized for simultaneous coordination to aldehyde carbonyls, thereby allowing the precise enantioface discrimination of such carbonyls for a new catalytic, practical enantioselective allylation of aldehydes with allyltributyltin. This chiral bidentate Ti(IV) catalyst exhibits uniformly high asymmetric induction as well as high chemical yields for various aldehydes. The present enantioselective allylation is highly chemoselective in the presence of other carbonyl moieties.

scholarly journals Enantioselective Nazarov cyclization of indole enones cooperatively catalyzed by Lewis acids and chiral Brønsted acids

2017 ◽  
Vol 8 (10) ◽  
pp. 7197-7202 ◽  
Author(s):  
Guo-Peng Wang ◽  
Meng-Qing Chen ◽  
Shou-Fei Zhu ◽  
Qi-Lin Zhou
Keyword(s):  
Proton Transfer ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Bronsted Acids ◽  
Bronsted Acid ◽  
Nazarov Cyclization ◽  
Cooperative Catalysis ◽  
Brönsted Acid ◽  
Chiral Bronsted Acid ◽  
Chiral Brønsted Acids

The first enantioselective Nazarov cyclization of substrates with only one coordinating site and with proton-transfer as an enantioselective-determining step was realized by means of cooperative catalysis with a Lewis acid and a chiral Brønsted acid.

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

2017 ◽  
Vol 19 (17) ◽  
pp. 3993-3996 ◽  
Author(s):  
D. J. M. Lyons ◽  
R. D. Crocker ◽  
D. Enders ◽  
T. V. Nguyen
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Tropylium Salts

Tropylium salts were reported as organic-Lewis acids to efficiently catalyze acetalization reactions in batch and flow.

scholarly journals Catalytic role of solid acid catalysts in glycerol acetylation for the production of bio-additives: a review

RSC Advances ◽  
2016 ◽  
Vol 6 (73) ◽  
pp. 68885-68905 ◽  
Author(s):  
Pei San Kong ◽  
Mohamed Kheireddine Aroua ◽  
Wan Mohd Ashri Wan Daud ◽  
Hwei Voon Lee ◽  
Patrick Cognet ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Lewis Acid ◽  
Solid Acid ◽  
Operating Conditions ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Bronsted Acid ◽  
Brönsted Acid ◽  
Catalytic Role

The influencing factors of Brønsted acid and Lewis acid in glycerol acetylation to potential bioadditives (mono-, di- and triacetin) are detailed. The important catalytic role and operating conditions toward conversion and selectivity are suggested.

Electrophilic phenoxy-substituted phosphonium cations

2016 ◽  
Vol 45 (45) ◽  
pp. 18156-18162 ◽  
Author(s):  
James H. W. LaFortune ◽  
Timothy C. Johnstone ◽  
Manuel Pérez ◽  
Daniel Winkelhaus ◽  
Vitali Podgorny ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Phosphonium Salts ◽  
Lewis Acid Catalysts ◽  
Phosphonium Cations

A family of electrophilic phenoxy-substituted phosphonium salts [(RO)P(C6F5)3][B(C6F5)4] (R = C6H5, 4-FC6H4, 2,4-F2C6H3, C6F5) have been synthesized, used as Lewis acid catalysts and their air stability was evaluated.

scholarly journals Defunctionalisation catalysed by boron Lewis acids

2020 ◽  
Vol 11 (47) ◽  
pp. 12604-12615 ◽  
Author(s):  
Huaquan Fang ◽  
Martin Oestreich
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

The combination of boron Lewis acid catalysts and hydride sources enables the cleavage of various carbon–heteroatom bonds.

Electrophilic Phosphonium Cations as Lewis Acid Catalysts in Diels–Alder Reactions and Nazarov Cyclizations

2018 ◽  
Vol 37 (19) ◽  
pp. 3303-3313 ◽  
Author(s):  
Maria Vogler ◽  
Lars Süsse ◽  
James H. W. LaFortune ◽  
Douglas W. Stephan ◽  
Martin Oestreich
Keyword(s):  
Lewis Acid ◽  
Diels Alder ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Nazarov Cyclizations ◽  
Phosphonium Cations
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