Sustainable synthesis of CO2-derived polycarbonates from d-xylose

2021 ◽  
Author(s):  
David K. Tran ◽  
Ahmed Z. Rashad ◽  
Donald J. Darensbourg ◽  
Karen L. Wooley
Keyword(s):  
Ring Opening ◽  
Cyclic Carbonate ◽  
Cyclic Ether ◽  
Synthetic Transformation

Synthetic transformation of d-xylose into a four-membered cyclic ether allows for reactions with CO2 leading to linear polycarbonates by either ring-opening copolymerisation directly or by isolation of a six-membered cyclic carbonate followed by ring-opening polymerisation.

Participation of 19-ester groups in the cleavage of 2α,3α- and 5α,6α-steroid epoxides. A case of competition between participation and external nucleophile attack

1979 ◽  
Vol 44 (5) ◽  
pp. 1496-1509 ◽  
Author(s):  
Pavel Kočovský ◽  
Václav Černý
Keyword(s):  
Perchloric Acid ◽  
Hydrobromic Acid ◽  
Ester Group ◽  
Carbonyl Oxygen ◽  
Cyclic Carbonate ◽  
Cyclic Ether ◽  
Normal Reaction ◽  
Neighboring Group ◽  
Ether Oxygen ◽  
The Difference

Acid cleavage of the acetoxy epoxide IIIa with aqueous perchloric acid or hydrobromic acid gave two types of products, i.e. the diol Va or the bromohydrin VIa, and the cyclic ether VIII. The latter compound arises by participation of ether oxygen of the ester group. On reaction with perchloric acid the epoxide IVa gave the diol XIIIa as a product of a normal reaction and the isomeric diol Xa as a product arising by intramolecular participation of the carbonyl oxygen of the 19-acetoxy group. Participation of the 19-ester group is confirmed by the formation of the cyclic carbonate XI when the 19-carbonate IVb is treated analogously. On reaction with hydrobromic acid, the epoxide IVa gave solely the bromohydrin XIVa as a product of the normal reaction course. Discussed is the similarity of these reactions with electrophilic additions to the related 19-acetoxy olefins I and II, the mechanism, the difference in behavior of both epoxides III and IV, the dependence of the product ratio on the nucleophility of the attacking species, and the competition between participation of an ambident neighboring group and an external nucleophile attack.

scholarly journals Synthesis, Characterization, and Antimicrobial Evaluation of Random Poly(ester-Carbonate)s Bearing Pendant Primary Amine in the Main Chain

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2640
Author(s):  
Peng Dong ◽  
Jing Feng ◽  
Sujuan Li ◽  
Tingli Sun ◽  
Qingshan Shi ◽  
...  
Keyword(s):  
Primary Amine ◽  
Ring Opening ◽  
Inhibitory Concentration ◽  
Cyclic Carbonate ◽  
Random Copolymers ◽  
Feed Ratio ◽  
E Coli ◽  
Antimicrobial Evaluation ◽  
Low Cytotoxicity ◽  
Poly Caprolactone

Starting from primary amine bearing cyclic carbonate tert-butyl-(2-oxo-1,3-dioxan-5-yl) carbamate (TBODC) and caprolactone (CL), amphiphilic poly(caprolactone-ran-amino trimethyl carbonate)s (P(CL-ran-ATC)s) random copolymers with controlled molecular weight and composition were synthesized via ring opening polymerization (ROP) and deprotection, using stannous octoate (Sn(Oct)2) as catalyst and benzyl alcohol (BnOH) as initiator. Therefore, hydrophilic/lipophilic ratio (HLR) of the P(CL-ran-ATC)s copolymers can be finely adjusted by the feed ratio of TBODC and CL. The antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) of P(CL-ran-ATC)s were proportional to HLR, and P(CL-ran-ATC)s presented more vigorous bactericidal activity towards S. aureus. The minimum inhibitory concentration (MIC) values of P(CL-ran-ATC 50.9%) are 2000 μg mL−1 and 3000 μg mL−1 for S. aureus and E. coli. While P(CL-ran-ATC 50.9%) exhibited deficient hemolytic activity as 1.41%. In addition, the P(CL-ran-ATC)s showed extremely low cytotoxicity towards fibroblast L929 cells.

Cyclic carbonates as monomers for phosgene- and isocyanate-free polyurethanes and polycarbonates

2011 ◽  
Vol 84 (3) ◽  
pp. 637-661 ◽  
Author(s):  
Sang-Hyun Pyo ◽  
Per Persson ◽  
M. Amin Mollaahmad ◽  
Kent Sörensen ◽  
Stefan Lundmark ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Performance ◽  
Optical Devices ◽  
Cyclic Carbonate ◽  
Cyclic Carbonates ◽  
Catalyst Metal ◽  
Recent Developments ◽  
Metallic Catalyst ◽  
Low Toxicity ◽  
Safety Procedures

Polyurethanes and polycarbonates are widely used in a variety of applications including engineering, optical devices, and high-performance adhesives and coatings, etc., and are expected to find use also in the biomedical field owing to their biocompatibility and low toxicity. However, these polymers are currently produced using hazardous phosgene and isocyanates, which are derived from the reaction between an amine and phosgene. Extensive safety procedures are required to prevent exposure to phosgene and isocyanate because of its high toxicity. Therefore, the demand for the production of isocyanate-free polymers has now emerged. Among the alternative greener routes that have been proposed, a popular way is the ring-opening polymerization (ROP) of cyclic carbonate in bulk or solution, usually using metallic catalyst, metal-free initiator, or biocatalyst. This review presents the recent developments in the preparation and application of cyclic carbonates as monomers for ROP, with emphasis on phosgene- and isocyanate-free polymerization to produce aliphatic polycarbonates and polyurethanes and their copolymers.

scholarly journals Zirconium (IV) Acetylacetonate: Ring-Opening Initiator Mediating One-Step Synthesis of Biodegradable Polyacids

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Piotr Dobrzyński ◽  
Małgorzata Pastusiak ◽  
Joanna Jaworska ◽  
Bożena Kaczmarczyk ◽  
Michał Kwiecień ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Acid Derivative ◽  
Ring Opening ◽  
Active Catalyst ◽  
Ring Opening Polymerization ◽  
Cyclic Carbonate ◽  
Trimethylene Carbonate ◽  
Step Method ◽  
Polymerization Mechanism ◽  
One Step

Biodegradable polyacid is obtained in one-step ring-opening polymerization (ROP) of carboxylic-acid-functionalized six-membered cyclic carbonate mediated with zirconium (IV) acetylacetonate. Exemplary copolymers with L,L-lactide are described as well. Moreover, zirconium (IV) acetylacetonate is found to be active catalyst of trimethylene carbonate (TMC) ROP in presence of carboxylic acid yielding PTMC end-capped with the acid derivative. Polymerization mechanism is hypothesized demonstrating possibilities of the method in work-saving polycation synthesis and one-step method of conjugate synthesis of well-known biocompatible polyesters and polycarbonates.

ChemInform Abstract: Magnesium Halide-Promoted Ring-Opening Reaction of Cyclic Ether in the Presence of Phosphine Halide.

ChemInform ◽  
2016 ◽  
Vol 47 (2) ◽  
Author(s):  
Yu-Chang Chang ◽  
Chia-Ming Weng ◽  
Tanveer M. Shaikh ◽  
Fung-E Hong
Keyword(s):  
Ring Opening ◽  
Cyclic Ether ◽  
Ring Opening Reaction ◽  
Magnesium Halide

Organophosphate-catalyzed bulk ring-opening polymerization as an environmentally benign route leading to block copolyesters, end-functionalized polyesters, and polyester-based polyurethane

2015 ◽  
Vol 6 (24) ◽  
pp. 4374-4384 ◽  
Author(s):  
Tatsuya Saito ◽  
Yusuke Aizawa ◽  
Kenji Tajima ◽  
Takuya Isono ◽  
Toshifumi Satoh
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Cyclic Carbonate ◽  
Environmentally Benign ◽  
Cyclic Ester ◽  
Cyclic Esters

To expand the potential of an organophosphate catalyst, ring-opening polymerization of cyclic esters, cyclic ester-ether, and cyclic carbonate was demonstrated under bulk conditions.

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