A strong cationic Brønsted acid, [H(OEt2)2][Al{OC(CF3)3}4], as an efficient initiator for the cationic ring-opening polymerization of 2-alkyl-2-oxazolines

2013 ◽  
Vol 4 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Tobias Rudolph ◽  
Kristian Kempe ◽  
Sarah Crotty ◽  
Renzo M. Paulus ◽  
Ulrich S. Schubert ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Cationic Ring Opening Polymerization

2,4-Dinitrobenzenesulfonic acid in an efficient Brønsted acid-catalyzed controlled/living ring-opening polymerization of ε-caprolactone

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 55716-55722 ◽  
Author(s):  
Huiying Wang ◽  
Wenzhuo Wu ◽  
Zhenjiang Li ◽  
Xu Zhi ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Ring Opening ◽  
Diblock Copolymers ◽  
Ring Opening Polymerization ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Acidic Catalyst ◽  
Brönsted Acid ◽  
Acid Catalyzed

2,4-Dinitrobenzenesulfonic acid as an efficient Brønsted acidic catalyst has been evaluated for the controlled/living ring-opening polymerization of ε-caprolactone end-functionalized, α,ω-dihydroxy telechelic poly(ε-caprolactone), and diblock copolymers were also synthesised successfully.

Three is company: dual intramolecular hydrogen-bond enabled carboxylic acid active in ring-opening polymerization

2016 ◽  
Vol 7 (5) ◽  
pp. 1111-1120 ◽  
Author(s):  
Jiaxi Xu ◽  
Jingjing Liu ◽  
Zhenjiang Li ◽  
Xiaopei Li ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Intramolecular Hydrogen Bond ◽  
Ring Opening ◽  
Active Catalyst ◽  
Ring Opening Polymerization ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Intramolecular Hydrogen

Dual intramolecular H-bonding made weak Brønsted acid an active catalyst in cationic ring-opening polymerizations.

scholarly journals Solventless Sol-Gel Chemistry Through Ring-Opening Polymerization of Bridged Disilaoxacyclopentanes

2000 ◽  
Vol 628 ◽  
Author(s):  
Kamyar Rahimian ◽  
Douglas A. Loy
Keyword(s):  
Ring Opening ◽  
Sol Gel ◽  
Ring Opening Polymerization ◽  
Inorganic Materials ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Organic Base ◽  
Triflic Acid ◽  
Brönsted Acid

Ring-opening polymerization (ROP) of disilaoxacyclopentanes has proven to be an excellent approach to sol-gel type hybrid orgainc-inorganic materials [1]. These materials have shown promise as precursors for encapsulation and microelectronics applications (Figure 1). The polymers are highly crosslinked and are structurally similar to traditional sol-gels, but unlike typical sol-gels they are prepared by an organic base or Bronsted acid (formic or triflic acid), without the use of solvents and water, they have low VOC's and show little shrinkage during processing.

Ring-Opening Hydroarylation of Monosubstituted Cyclopropanes Enabled by Hexafluoroisopropanol

2018 ◽  
Author(s):  
Edward Richmond ◽  
Jing Yi ◽  
Vuk D. Vuković ◽  
Fatima Sajadi ◽  
Christopher Rowley ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Ring Opening ◽  
Bond Formation ◽  
Conjugate Addition ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Broad Scope ◽  
Brönsted Acid ◽  
Donor Acceptor ◽  
Addition Pathway

<div><p>Ring-opening hydroarylation of cyclopropanes is typically limited to substrates bearing a donor-acceptor motif. Here, the transformation is achieved for monosubstituted cyclopropanes by using catalytic Brønsted acid in hexafluoroisopropanol (HFIP) solvent, constituting a rare example where such cyclopropanes engage in intermolecular C–C bond formation. Branched products are obtained when electron-rich arylcyclopropanes react with a broad scope of arene nucleophiles in accord with a simple S<sub>N</sub>1-type ring-opening mechanism. In constrast, linear products are obtained when cyclopropylketones react with electron-rich arene nucleophiles. In the latter case, mechanistic experiments and DFT-calculations support a homo-conjugate addition pathway.</p></div>

Brønsted acid-catalysed intramolecular ring opening of 2-(aryloxymethyl)-3-aryloxiranes leading to trans-4-arylchroman-3-ols: scope and limitations

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39692-39696 ◽  
Author(s):  
Runjun Devi ◽  
Tapasi Kalita ◽  
Sajal Kumar Das
Keyword(s):  
Ring Opening ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Metal Free ◽  
Brönsted Acid ◽  
Intramolecular Ring

A simple and metal-free method for the synthesis of a series oftrans-4-arylchroman-3-olsviaBrønsted acid-catalysed stereoselective intramolecular Friedel–Crafts alkylation of electron-rich arenes by tethered epoxides is developed.

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