Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Direct synthesis of polyamides via catalytic dehydrogenation of diols and diamines.

ABSTRACT: We report a direct synthesis of polyamides via catalytic dehydrogenation of diols and diamines. A PNN pincer ruthenium complex, the Milstein catalyst, was used for this reaction and polyamides with number average molecular weight from ?10 to 30 kDa could be obtained from a wide variety of diols and diamines bearing aliphatic or aromatic, linear or cyclic spacers. Because of the high catalytic selectivity of primary amine over secondary amine, polyamines could be conveniently incorporated into linear polyamides without tedious protection/deprotection steps. Compared with conventional condensation method, this catalytic system avoids the requirement of stoichiometric preactivation or in situ activation reagents and provides a much cleaner process with high atomic economy.

SUBMITTER: Zeng H

PROVIDER: S-EPMC3033491 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Direct synthesis of polyamides via catalytic dehydrogenation of diols and diamines.

Zeng Hanxiang H Guan Zhibin Z

Journal of the American Chemical Society 20110104 5

We report a direct synthesis of polyamides via catalytic dehydrogenation of diols and diamines. A PNN pincer ruthenium complex, the Milstein catalyst, was used for this reaction and polyamides with number average molecular weight from ∼10 to 30 kDa could be obtained from a wide variety of diols and diamines bearing aliphatic or aromatic, linear or cyclic spacers. Because of the high catalytic selectivity of primary amine over secondary amine, polyamines could be conveniently incorporated into li ...[more]

PMID: 21204554

Similar Datasets

Synthesis of cyclic enones via direct palladium-catalyzed aerobic dehydrogenation of ketones.

Project description:α,β-Unsaturated carbonyl compounds are versatile intermediates in the synthesis of pharmaceuticals and biologically active compounds. Here, we report the discovery and application of Pd(DMSO)(2)(TFA)(2) as a catalyst for direct dehydrogenation of cyclohexanones and other cyclic ketones to the corresponding enones, using O(2) as the oxidant. The substrate scope includes heterocyclic ketones and several natural-product precursors.

| S-EPMC3173566 | biostudies-literature

Direct synthesis of <i>p</i>-methyl benzaldehyde from acetaldehyde via an organic amine-catalyzed dehydrogenation mechanism.

Project description:p-Methyl benzaldehyde (p-MBA) is a class of key chemical intermediates of pharmaceuticals. Conventional industrial processes for p-MBA production involve the consecutive photochlorination, amination, and acid hydrolysis of petroleum-derived p-xylene, while producing vast pollutants and waste water. Herein, we report a direct, green route for selective synthesis of p-MBA from acetaldehyde using a diphenyl prolinol trimethylsilyl ether catalyst. The optimized p-MBA selectivity is up to 90% at an acetaldehyde conversion as high as 99.8%. Intermediate structure and 18O-isotope data revealed that the conversion of acetaldehyde to p-methylcyclohexadienal intermediates proceeds in an enamine-iminium intermediate mechanism. Then, controlled experiments and D-isotope results indicated that the dehydrogenation of p-methylcyclohexadienal to p-MBA and H2 is catalyzed by the same amines through an iminium intermediate. This is an example that metal-free amines catalyze the dehydrogenation (releasing H2), rather than using metals or stoichiometric oxidants.

| S-EPMC8426279 | biostudies-literature

Catalytic, enantioselective synthesis of 1,2-anti-diols by asymmetric ring-opening/cross-metathesis.

Project description:An enantioselective method for the synthesis of 1,2-anti-diols has been developed. A cyclometalated chiral-at-ruthenium complex catalyzes the asymmetric ring-opening/cross-metathesis of dioxygenated cyclobutenes, thus resulting in functionally rich synthetic building blocks. Syntheses of the insect pheromone (+)-endo-brevicomin and monosaccharide ribose demonstrate the synthetic utility of the 1,2-anti-diol fragments generated in the title reaction.

| S-EPMC4037230 | biostudies-literature

Regiodivergent reactions through catalytic enantioselective silylation of chiral diols. Synthesis of sapinofuranone A.

Project description:Through the use of an amino acid based imidazole catalyst, a regiodivergent silylation of chiral diols in cases where there is not a significant steric and electronic difference between the regioisotopic hydroxyl groups has been developed. This transformation allows for the conversion of racemic diols into regioisomeric, enantiomerically enriched, monosilylated products. The utility of this process is highlighted in the efficient enantioselective preparation of a useful synthetic intermediate and the natural product, sapinofuranone A.

| S-EPMC3146572 | biostudies-literature

Direct Catalytic Asymmetric Synthesis of Trifluoromethylated γ-Amino Esters/Lactones via Umpolung Strategy.

Project description:Enabled by the discovery of new cinchonium salts and coadditives, a direct and efficient asymmetric access to trifluoromethylated γ-amino esters/lactones has been realized through the enantioselective and diastereoselective umpolung reaction of trifluoromethyl imines with acrylates or α,β-unsaturated lactones as carbon electrophiles. At 0.5-5.0 mol % catalyst loadings, the newly developed catalytic system activates a variety of imine substrates as unconventional nucleophiles to mediate highly chemo-, regio-, diastereo-, and enantioselective C-C bond forming reactions. The developed synthetic protocol represents an excellent strategy to target a series of versatile and enantiomerically enriched γ-amino esters/lactones in good to excellent yields from the readily available starting materials. Additionally, we found that the epi-vinyl catalysts based on cinchonidine and quinine promote a similarly high enantioselective reaction generating the opposite configuration of chiral products in a highly efficient manner, which allows convenient access to either the R- or S-enantiomer of the chiral amine products in high yields and excellent enantioselectivities.

| S-EPMC6467775 | biostudies-literature

Bacterial synthesis of C3-C5 diols via extending amino acid catabolism.

Project description:Amino acids are naturally occurring and structurally diverse metabolites in biological system, whose potentials for chemical expansion, however, have not been fully explored. Here, we devise a metabolic platform capable of producing industrially important C3-C5 diols from amino acids. The presented platform combines the natural catabolism of charged amino acids with a catalytically efficient and thermodynamically favorable diol formation pathway, created by expanding the substrate scope of the carboxylic acid reductase toward noncognate ω-hydroxylic acids. Using the established platform as gateways, seven different diol-convertible amino acids are converted to diols including 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. Particularly, we afford to optimize the production of 1,4-butanediol and demonstrate the de novo production of 1,5-pentanediol from glucose, with titers reaching 1.41 and 0.97 g l-1, respectively. Our work presents a metabolic platform that enriches the pathway repertoire for nonnatural diols with feedstock flexibility to both sugar and protein hydrolysates.

| S-EPMC7431042 | biostudies-literature

Direct Copolymerization of CO2 and Diols.

Project description:Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 ?,?-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification.

| S-EPMC4831014 | biostudies-literature

Direct catalytic asymmetric synthesis of pyrazolidine derivatives.

Project description: Not available

| S-EPMC3922451 | biostudies-literature

Acceptorless Dehydrogenative Coupling Using Ammonia: Direct Synthesis of N-Heteroaromatics from Diols Catalyzed by Ruthenium.

Project description:The synthesis of N-heteroaromatic compounds via an acceptorless dehydrogenative coupling process involving direct use of ammonia as the nitrogen source was explored. We report the synthesis of pyrazine derivatives from 1,2-diols and the synthesis of N-substituted pyrroles by a multicomponent dehydrogenative coupling of 1,4-diols and primary alcohols with ammonia. The acridine-based Ru-pincer complex 1 is an effective catalyst for these transformations, in which the acridine backbone is converted to an anionic dearomatized PNP-pincer ligand framework.

| S-EPMC6502445 | biostudies-literature

Catalytic, Enantioselective Synthesis of Stilbene cis-Diamines: A Concise Preparation of (-)-Nutlin-3, a Potent p53/MDM2 Inhibitor.

Project description:The first highly diastereo- and enantioselective additions of aryl nitromethane pronucleophiles to aryl aldimines are described. Identification of an electron rich chiral Bis(Amidine) catalyst for this aza-Henry variant was key to this development, leading ultimately to differentially protected cis-stilbene diamines in two steps. This method then became the lynchpin for an enantioselective synthesis of (-)-Nutlin-3 (Hoffmann-LaRoche), a potent cis-imidazoline small molecule inhibitor of p53-MDM2 used extensively as a probe of cell biology and currently in drug development.

| S-EPMC3375951 | 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