scholarly journals DFT investigation of the reaction mechanism for the guanidine catalysed ring-opening of cyclic carbonates by aromatic and alkyl-amines

RSC Advances ◽  
2017 ◽  
Vol 7 (31) ◽  
pp. 18993-19001 ◽  
Author(s):  
M. Alves ◽  
R. Méreau ◽  
B. Grignard ◽  
C. Detrembleur ◽  
C. Jérôme ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Ring Opening ◽  
Cyclic Carbonates ◽  
Alkyl Amines

The bifunctional activity (base/H-bond donor) of TBD allows understanding its higher efficiency compared to its methyl counterpart (MTBD) for the aminolysis of cyclic carbonates by amines.

scholarly journals Ring-Opening Copolymerization of Cyclohexene Oxide and Cyclic Anhydrides Catalyzed by Bimetallic Scorpionate Zinc Catalysts

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1651
Author(s):  
Felipe de la Cruz-Martínez ◽  
Marc Martínez de Sarasa Buchaca ◽  
Almudena del Campo-Balguerías ◽  
Juan Fernández-Baeza ◽  
Luis F. Sánchez-Barba ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Catalytic System ◽  
Phthalic Anhydride ◽  
Ring Opening ◽  
High Selectivity ◽  
Zinc Complexes ◽  
Cyclohexene Oxide ◽  
Reaction Conditions ◽  
Cyclic Anhydrides

The catalytic activity and high selectivity reported by bimetallic heteroscorpionate acetate zinc complexes in ring-opening copolymerization (ROCOP) reactions involving CO2 as substrate encouraged us to expand their use as catalysts for ROCOP of cyclohexene oxide (CHO) and cyclic anhydrides. Among the catalysts tested for the ROCOP of CHO and phthalic anhydride at different reaction conditions, the most active catalytic system was the combination of complex 3 with bis(triphenylphosphine)iminium as cocatalyst in toluene at 80 °C. Once the optimal catalytic system was determined, the scope in terms of other cyclic anhydrides was broadened. The catalytic system was capable of copolymerizing selectively and efficiently CHO with phthalic, maleic, succinic and naphthalic anhydrides to afford the corresponding polyester materials. The polyesters obtained were characterized by spectroscopic, spectrometric, and calorimetric techniques. Finally, the reaction mechanism of the catalytic system was proposed based on stoichiometric reactions.

Latest Research and Developing Tendency of Hyperbranched Polymers Fabrication

2021 ◽  
Vol 896 ◽  
pp. 45-50
Author(s):  
Lian Yi Huo ◽  
Xue Tao Shi ◽  
Si Ming Chen ◽  
Meng Yao Zhang
Keyword(s):  
Reaction Mechanism ◽  
Ring Opening ◽  
Hyperbranched Polymers ◽  
Ring Opening Polymerization ◽  
Synthesis Process ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Environmental Friendly ◽  
High Efficient ◽  
The Future

Hyperbranched polymers (HBPs) have been applied in various fields because of its outstanding biodegradability and biocompatibility. At present, there are a variety of methods that are used to fabricate HBPs, such as polycondensation, reactive polymerization and ring-opening polymerization according to reaction mechanism. These methods are all environmental-friendly and high-efficient to generate HBPs, and are valuable for industrialization. In this work, we conclude some common methods of HBPs fabrication and make the comparison between them to analyze their advantages and disadvantages, which contribute in how to improve the synthesis process in the future research.

Molecular Rearrangements. Part IV. Aryl (Alkyl) Amines (1), Thermal Rearrangement of N-Benzyl-N-Methylaniline

1974 ◽  
Vol 52 (2) ◽  
pp. 293-298 ◽  
Author(s):  
M. Zarif A. Badr ◽  
M. M. Aly
Keyword(s):  
Free Radicals ◽  
Reaction Mechanism ◽  
Tertiary Amine ◽  
Thermal Rearrangement ◽  
Molecular Rearrangements ◽  
Intermediate Products ◽  
Alkyl Amines ◽  
Rearrangement Process ◽  
Homolytic Fission

Heating N-benzyl-N-methylaniline under reflux or heating at ∼315° in sealed tubes, in the absence of any promotor for 100 h, resulted in its rearrangement, producing methylamine, diphenylmethane, and dibenzyl together with o-toluidine and 4-methylacridine. Heating N-methylaniline in a sealed tube under the same conditions, in absence of any promotor, resulted in its rearrangement, producing methylamine and o-toluidine together with unidentified neutral products.When pyrolysis of the tertiary amine was carried out with quinoline as a solvent, the normal products of rearrangement were obtained together with 2-and 4-benzylquinolines and 2,2′-biquinolyl.The reaction mechanism is discussed on the basis of the products separated, from which it is concluded that the tertiary amine undergoes homolytic fission to benzyl and N-methylphenylamino free radicals, followed by a series of homolytic fissions of initially separated intermediate products, during the rearrangement process. Throughout the whole mechanism, the C—N bonds are the only ones to suffer homolytic fission.

The ability of a zinc pyrrolidine complex to catalyze the synthesis of cyclic carbonates from carbon dioxide and epoxides: a mechanistic theoretical investigation

2017 ◽  
Vol 46 (28) ◽  
pp. 9030-9035 ◽  
Author(s):  
Tiziana Marino ◽  
Fortuna Ponte ◽  
Gloria Mazzone ◽  
Emilia Sicilia ◽  
Marirosa Toscano ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Reaction Mechanism ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Cyclic Carbonates ◽  
Functional Level

The reaction mechanism for the synthesis of cyclic carbonates from carbon dioxide and epoxides catalyzed by a zinc pyrrolidine complex has been elucidated using the density functional level of theory.

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.

Metal-catalyzed immortal ring-opening polymerization of lactones, lactides and cyclic carbonates

2010 ◽  
Vol 39 (36) ◽  
pp. 8363 ◽  
Author(s):  
Noureddine Ajellal ◽  
Jean-François Carpentier ◽  
Clémence Guillaume ◽  
Sophie M. Guillaume ◽  
Marion Helou ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Cyclic Carbonates ◽  
Metal Catalyzed

Ring-opening polymerization and copolymerization of cyclic carbonates

1991 ◽  
Vol 42-43 (1) ◽  
pp. 145-153 ◽  
Author(s):  
H. Höcker ◽  
H. Keul ◽  
S. Kuhllng ◽  
W. Hovestadt
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Cyclic Carbonates
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