Browse
Submit Data
Databases
API
Help

Dataset Information

39 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Dewar Heterocycles as Versatile Monomers for Ring-Opening Metathesis Polymerization.

ABSTRACT: We report the utility of readily available heterocycles as precursors to unique ring-opening metathesis polymerization (ROMP) monomers. Photochemical valence isomerization reactions of pyridones, dihydropyridines, and pyrones dearomatize the parent heterocycles to their highly strained Dewar isomers, which readily engage in controlled ROMP reactions using Grubbs catalysts. This strategy is used to access polymer backbones that contain strained β-lactam and azetidine cores, which can be further derivatized using post-polymerization chemistries. We demonstrate this through the synthesis of water-soluble β-amino acid polymers that have potential applications as biomedical materials, along with the synthesis of highly-soluble poly(acetylene) derivatives, which have potential applications as organic conductive materials derived from bio-feedstock chemicals.

SUBMITTER: Nistanaki SK

PROVIDER: S-EPMC8297915 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Dewar Heterocycles as Versatile Monomers for Ring-Opening Metathesis Polymerization.

Nistanaki Sepand K SK Nelson Hosea M HM

ACS macro letters 20200501 5

We report the utility of readily available heterocycles as precursors to unique ring-opening metathesis polymerization (ROMP) monomers. Photochemical valence isomerization reactions of pyridones, dihydropyridines, and pyrones dearomatize the parent heterocycles to their highly strained Dewar isomers, which readily engage in controlled ROMP reactions using Grubbs catalysts. This strategy is used to access polymer backbones that contain strained β-lactam and azetidine cores, which can be further d ...[more]

PMID: 34306822

Similar Datasets

Predicting Monomers for Use in Aqueous Ring-Opening Metathesis Polymerization-Induced Self-Assembly.

Project description:Aqueous polymerization-induced self-assembly (PISA) is a well-established methodology enabling in situ synthesis of polymeric nanoparticles of controllable morphology. Notably, PISA via ring-opening metathesis polymerization (ROMPISA) is an emerging technology for block copolymer self-assembly, mainly due to its high versatility and robustness. However, a limited number of monomers suitable for core-forming blocks in aqueous ROMPISA have been reported to date. In this work, we identified seven monomers for use as either corona- or core-forming blocks during aqueous ROMPISA by in silico calculation of relative hydrophobicity for corresponding oligomeric models. The predicted monomers were validated experimentally by conducting ROMPISA using our previously reported two-step approach. In addition to predictive data, our computational model was exploited to identify trends between polymer hydrophobicity and the morphology of the self-assembled nano-objects they formed. We expect that this methodology will greatly expand the scope of aqueous ROMPISA, as monomers can be easily identified based on the structure-property relationships observed herein.

| S-EPMC6471431 | biostudies-literature

Carbodiimide Ring-Opening Metathesis Polymerization.

Project description:Controlled incorporation of nitrogen into macromolecular skeletons is a long-standing challenge whose resolution would enable the preparation of soft materials with the scalability of man-made plastics and functionality of Nature's proteins. Nylons and polyurethanes notwithstanding, nitrogen-rich polymer backbones remain scarce, and their synthesis typically lacks precision. Here we report a strategy that begins to address this limitation founded on a mechanistic discovery: ring-opening metathesis polymerization (ROMP) of carbodiimides followed by carbodiimide derivatization. An iridium guanidinate complex was found to initiate and catalyze ROMP of N-aryl and N-alkyl cyclic carbodiimides. Nucleophilic addition to the resulting polycarbodiimides enabled the preparation of polyureas, polythioureas, and polyguanidinates with varied architectures. This work advances the foundations of metathesis chemistry and opens the door to systematic investigations of structure-folding-property relationships in nitrogen-rich macromolecules.

| S-EPMC10311665 | biostudies-literature

Correction to “Carbodiimide Ring-Opening Metathesis Polymerization”

Project description: Not available

| S-EPMC10450882 | biostudies-literature

Access to Bicyclo[4.2.0]octene Monomers To Explore the Scope of Alternating Ring-Opening Metathesis Polymerization.

Project description:Bicyclo[4.2.0]oct-1(8)-ene-8-carboxamides undergo alternating ring-opening metathesis polymerization (AROMP) with cyclohexene. Herein, a general method for the preparation of bicyclo[4.2.0]oct-(8)-ene-8-carboxy derivatives is described. The central 8-cyano intermediate provides entry to five different functional group substituents on the alkene. These monomers were tested as potential substrates for AROMP with cyclohexene. In addition to the carboxamide, the carboxynitrile and carboxaldehyde are also substrates for AROMP. In the case of the carboxaldehyde, the polymer is regioregular. However, the addition of carboxynitrile is stereoirregular and slow.

| S-EPMC5838619 | biostudies-literature

Practical Route for Catalytic Ring-Opening Metathesis Polymerization.

Project description:Norbornene derivatives are typical monomers for ring-opening metathesis polymerization (ROMP) for synthesizing highly functional polymers. However, the lack of catalytic methods, that is, the lack of readily available chain transfer agents (CTAs) for these monomers has been a significant cost limitation when large-scale syntheses are required. Here, we report commercially available styrene and its derivatives as efficient regioselective CTAs for the catalytic synthesis of metathesis polymers requiring up to 1000 times less ruthenium than in classical ROMP experiments. The molecular weight of the synthesized polymers was controlled by the monomer-to-CTA ratio. Low molecular weight ROMP polymers known for their antimicrobial properties were also synthesized on a gram scale in this report. Polymers were characterized by SEC, 1H NMR spectroscopy, and isotopically resolved MALDI-TOF MS. This approach describes a greener, more cost-effective, and eco-friendly methodology for the preparation of metathesis-based materials on the multigram scale.

| S-EPMC9795566 | biostudies-literature

Alternating Ring-Opening Metathesis Polymerization (AROMP) of Hydrophobic and Hydrophilic Monomers Provides Oligomers with Side-Chain Sequence Control.

Project description:We report the formation of oligomers with side-chain sequence control using ruthenium-catalyzed alternating ring-opening metathesis polymerization (AROMP). These oligomers are prepared through sequential, stoichiometric addition of bicyclo[4.2.0]oct-1(8)-ene-8-carboxamide (monomer A) at 85 °C and cyclohexene (monomer B) at 45 °C to generate sequences up to 24 monomeric units composed of (A-alt- B) n and (A'-alt-B) n microblocks, where n ranges from 1 to 6. Herein, monomer A has an alkyl side chain, and monomer A' has a glycine methyl ester side chain. Increasing microblock size from one to six results in an increasing water contact angle on spin-coated thin films, despite the constant ratio of hydrophilic and hydrophobic moieties. However, a disproportionately high contact angle was observed when n equals 2. Thus, the unique all-carbon backbone formed in the AROMP of bicyclo[4.2.0]oct-1(8)-ene-8-carboxamides and cyclohexene provides a platform for the nontemplated preparation of materials with specific sequences of side chains.

| S-EPMC6262599 | biostudies-literature

Metal-Free Ring-Opening Metathesis Polymerization with Hydrazonium Initiators.

Project description:The ring-opening metathesis polymerization (ROMP) of cyclopropenes using hydrazonium initiators is described. The initiators, which are formed by the condensation of 2,3-diazabicyclo[2.2.2]octane and an aldehyde, polymerize cyclopropene monomers by a sequence of [3+2] cycloaddition and cycloreversion reactions. This process generates short chain polyolefins (Mn ≤9.4 kg mol-1 ) with relatively low dispersities (Đ≤1.4). The optimized conditions showed efficiency comparable to that achieved with Grubbs' 2nd generation catalyst for the polymerization of 3-methyl-3-phenylcyclopropene. A positive correlation between monomer to initiator ratio and degree of polymerization was revealed through NMR spectroscopy.

| S-EPMC9149102 | biostudies-literature

Expedient Synthesis and Ring-Opening Metathesis Polymerization of Pyridinonorbornenes.

Project description:Pyridine-containing polymers are promising materials for a variety of applications from the capture of contaminants to the self-assembly of block copolymers. However, the innate Lewis basicity of the pyridine motif often hampers living polymerization catalyzed by transition-metal complexes. Herein, we report the expedient synthesis of pyridinonorbornene monomers via a [4+2] cycloaddition between 2,3-pyridynes and cyclopentadiene. Well-controlled ring-opening metathesis polymerization was enabled by careful structural design of the monomer. Polypyridinonorbornenes exhibited high Tg and Td, a promising feature for high-temperature applications. Investigation of the polymerization kinetics and of the reactivity of the chain ends shed light on the influence of nitrogen coordination on the chain-growth mechanism.

| S-EPMC10168028 | biostudies-literature

Resonance promoted ring-opening metathesis polymerization of twisted amides.

Project description:The living ring-opening metathesis polymerization (ROMP) of an unsaturated twisted amide using the third-generation Grubbs initiator is described. Unlike prior examples of ROMP monomers that rely on angular or steric strain for propagation, this system is driven by resonance destabilization of the amide that arises from geometric constraints of the bicyclic framework. Upon ring-opening, the amide can rotate and rehybridize to give a stabilized and planar conjugated system that promotes living propagation. The absence of other strain elements in the twisted amide is supported by the inability of a carbon analogue of the monomer to polymerize and computational studies that find resonance destabilization accounts for 11.3 kcal mol-1 of the overall 12.0 kcal mol-1 ring strain. The twisted amide polymerization is capable of preparing high molecular weight polymers rapidly at room temperature, and post-polymerization modification combined with 2D NMR spectroscopy confirms a regioirregular polymer microstructure.

| S-EPMC6993617 | biostudies-literature

Cis-selective ring-opening metathesis polymerization with ruthenium catalysts.

Project description:Cis-selective ring-opening metathesis polymerization of several monocyclic alkenes as well as norbornene and oxanorbornene-type monomers using a C-H activated, ruthenium-based metathesis catalyst is reported. The cis content of the isolated polymers depended heavily on the monomer structure and temperature. A cis content as high as 96% could be obtained by lowering the temperature of the polymerization.

| S-EPMC3278323 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data