Molecular design of chiral quaternary ammonium polymers for asymmetric catalysis applications

2012 ◽  
Vol 10 (14) ◽  
pp. 2870 ◽  
Author(s):  
Md. Masud Parvez ◽  
Naoki Haraguchi ◽  
Shinichi Itsuno
Keyword(s):  
Asymmetric Catalysis ◽  
Quaternary Ammonium ◽  
Molecular Design

scholarly journals Synthesis of Main-Chain Chiral Quaternary Ammonium Polymers for Asymmetric Catalysis Using Quaternization Polymerization

Molecules ◽  
2012 ◽  
Vol 17 (6) ◽  
pp. 7569-7583 ◽  
Author(s):  
Naoki Haraguchi ◽  
Parbhej Ahamed ◽  
Md. Masud Parvez ◽  
Shinichi Itsuno
Keyword(s):  
Asymmetric Catalysis ◽  
Quaternary Ammonium ◽  
Main Chain

scholarly journals A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis

2020 ◽  
Vol 59 (28) ◽  
pp. 11456-11461 ◽  
Author(s):  
Daisuke Uraguchi ◽  
Fumito Ueoka ◽  
Naoya Tanaka ◽  
Tomohito Kizu ◽  
Wakana Takahashi ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Molecular Design ◽  
Design Synthesis

scholarly journals A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis

2020 ◽  
Author(s):  
Daisuke Uraguchi ◽  
Fumito Ueoka ◽  
Naoya Tanaka ◽  
Tomohito Kizu ◽  
Wakana Takahashi ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Asymmetric Catalysis ◽  
Molecular Design ◽  
Design Strategy ◽  
Vinyl Ethers ◽  
Design Synthesis ◽  
Effective Catalyst ◽  
Structural Robustness ◽  
Selective Chemical ◽  
Selectivity Control

Catalysis by chiral weakly-coordinating anions (WCAs) remains underdeveloped due to the lack of a molecular design strategy for exploiting their characteristics, such as the non-nucleophilic nature. Here, we report the development of a chiral borate ion comprising an <i>O</i>,<i>N</i>,<i>N</i>,<i>O</i>-tetradentate backbone, which ensures hitherto unattainable structural robustness. Upon pairing with a proton, the hydrogen borate acts as an effective catalyst for the asymmetric Prins-type cyclization of vinyl ethers, providing access to structurally and stereochemically defined dihydropyrans. The key to selectivity control is the distinct ability of the borate ion to discriminate the prochiral faces of the acyclic oxonium ion intermediate and dictate the regiochemical outcome. We anticipate that this study paves the way for exploring the untapped potential of WCA catalysis for selective chemical synthesis.<br>

scholarly journals Rational molecular design of anion exchange membranes functionalized with alicyclic quaternary ammonium cations

2020 ◽  
Vol 11 (43) ◽  
pp. 6953-6963
Author(s):  
Thanh Huong Pham ◽  
Andrit Allushi ◽  
Joel S. Olsson ◽  
Patric Jannasch
Keyword(s):  
Anion Exchange ◽  
Quaternary Ammonium ◽  
Molecular Design ◽  
Polymer Membranes ◽  
Anion Exchange Membranes ◽  
Quaternary Ammonium Cations ◽  
Alkaline Stability ◽  
Rational Molecular Design

Piperidine-based cations tethered to ether-free polymer membranes via the 4-position instead of the conventional 1(N)-position show significantly improved thermal and alkaline stability while retaining high hydroxide conductivity.

Molecular Design, Synthesis, and Asymmetric Catalysis of a Hexacoordinated Chiral Phosphate Ion

2018 ◽  
Vol 140 (8) ◽  
pp. 2765-2768 ◽  
Author(s):  
Daisuke Uraguchi ◽  
Hitoshi Sasaki ◽  
Yuto Kimura ◽  
Takaki Ito ◽  
Takashi Ooi
Keyword(s):  
Asymmetric Catalysis ◽  
Molecular Design ◽  
Design Synthesis ◽  
Phosphate Ion

scholarly journals A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis

2020 ◽  
Author(s):  
Daisuke Uraguchi ◽  
Fumito Ueoka ◽  
Naoya Tanaka ◽  
Tomohito Kizu ◽  
Wakana Takahashi ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Asymmetric Catalysis ◽  
Molecular Design ◽  
Design Strategy ◽  
Vinyl Ethers ◽  
Design Synthesis ◽  
Effective Catalyst ◽  
Structural Robustness ◽  
Selective Chemical ◽  
Selectivity Control

Catalysis by chiral weakly-coordinating anions (WCAs) remains underdeveloped due to the lack of a molecular design strategy for exploiting their characteristics, such as the non-nucleophilic nature. Here, we report the development of a chiral borate ion comprising an <i>O</i>,<i>N</i>,<i>N</i>,<i>O</i>-tetradentate backbone, which ensures hitherto unattainable structural robustness. Upon pairing with a proton, the hydrogen borate acts as an effective catalyst for the asymmetric Prins-type cyclization of vinyl ethers, providing access to structurally and stereochemically defined dihydropyrans. The key to selectivity control is the distinct ability of the borate ion to discriminate the prochiral faces of the acyclic oxonium ion intermediate and dictate the regiochemical outcome. We anticipate that this study paves the way for exploring the untapped potential of WCA catalysis for selective chemical synthesis.<br>

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