Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Sequential Ruthenium Catalysis for Olefin Isomerization and Oxidation: Application to the Synthesis of Unusual Amino Acids.

ABSTRACT: How can you use a ruthenium isomerization catalyst twice? A ruthenium-catalyzed sequence for the formal two-carbon scission of allyl groups to carboxylic acids has been developed. The reaction includes an initial isomerization step using commercially available ruthenium catalysts followed by in situ transformation of the complex to a metal-oxo species, which is capable of catalyzing subsequent oxidation reactions. The method enables enantioselective syntheses of challenging ?-tri- and tetrasubstituted ?-amino acids including an expedient total synthesis of the antiepileptic drug levetiracetam.

SUBMITTER: Liniger M

PROVIDER: S-EPMC5628162 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Sequential Ruthenium Catalysis for Olefin Isomerization and Oxidation: Application to the Synthesis of Unusual Amino Acids.

Liniger Marc M Liu Yiyang Y Stoltz Brian M BM

Journal of the American Chemical Society 20170925 39

How can you use a ruthenium isomerization catalyst twice? A ruthenium-catalyzed sequence for the formal two-carbon scission of allyl groups to carboxylic acids has been developed. The reaction includes an initial isomerization step using commercially available ruthenium catalysts followed by in situ transformation of the complex to a metal-oxo species, which is capable of catalyzing subsequent oxidation reactions. The method enables enantioselective syntheses of challenging α-tri- and tetrasubst ...[more]

PMID: 28918631

Similar Datasets

Cycle-specific organocascade catalysis: application to olefin hydroamination, hydro-oxidation, and amino-oxidation, and to natural product synthesis.

Project description:United in effort: The combined application of iminium (Im) and enamine (En) catalysts can effect a range of valuable asymmetric transformations including 1,2-hydroamination, -hydro-oxidation, and -amino-oxidation of olefins (see picture). An enantioselective organocascade catalysis was also applied in the synthesis of a complex natural product.

| S-EPMC3057093 | biostudies-literature

Catalytic Decomposition of Long-Chain Olefins to Propylene via Isomerization-Metathesis Using Latent Bicyclic (Alkyl)(Amino)Carbene-Ruthenium Olefin Metathesis Catalysts.

Project description:One of the most exciting scientific challenges today is the catalytic degradation of non-biodegradable polymers into value-added chemical feedstocks. The mild pyrolysis of polyolefins, including high-density polyethylene (HDPE), results in pyrolysis oils containing long-chain olefins as major products. In this paper, novel bicyclic (alkyl)(amino)carbene ruthenium (BICAAC-Ru) temperature-activated latent olefin metathesis catalysts, which can be used for catalytic decomposition of long-chain olefins to propylene are reported. These thermally stable catalysts show significantly higher selectivity to propylene at a reaction temperature of 75 °C compared to second generation Hoveyda-Grubbs or CAAC-Ru catalysts under ethenolysis conditions. The conversion of long-chain olefins (e.g., 1-octadecene or methyl oleate) to propylene via isomerization-metathesis is performed by using a (RuHCl)(CO)(PPh3 )3 isomerization co-catalyst. The reactions can be carried out at a BICAAC-Ru catalyst loading as low as 1 ppm at elevated reaction temperature (75 °C). The observed turnover number and turnover frequency are as high as 55 000 and 10 000 molpropylene molcatalyst -1 h-1 , respectively.

| S-EPMC9400880 | biostudies-literature

Asymmetric olefin isomerization of butenolides via proton transfer catalysis by an organic molecule.

Project description:An unprecedented enantioselective and general olefin isomerization was realized via biomimetic proton transfer catalysis with a new chiral organic catalyst. A broad range of mono- and disubstituted β,γ-unsaturated butenolides were transformed into the corresponding chiral α,β-unsaturated butenolides in high enantioselectivity and yield in the presence of as low as 0.5 mol % catalyst. Mechanistic studies have revealed the protonation as the rate-determining step.

| S-EPMC3156085 | biostudies-literature

Water co-catalysis in aerobic olefin epoxidation mediated by ruthenium oxo complexes.

Project description:We report the development of a versatile Ru-porphyrin catalyst system which performs the aerobic epoxidation of aromatic and aliphatic (internal) alkenes under mild conditions, with product yields of up to 95% and turnover numbers (TON) up to 300. Water is shown to play a crucial role in the reaction, significantly increasing catalyst efficiency and substrate scope. Detailed mechanistic investigations employing both computational studies and a range of experimental techniques revealed that water activates the RuVI di-oxo complex for alkene epoxidation via hydrogen bonding, stabilises the RuIV mono-oxo intermediate, and is involved in the regeneration of the RuVI di-oxo complex leading to oxygen atom exchange. Distinct kinetics are obtained in the presence of water, and side reactions involved in catalyst deactivation have been identified.

| S-EPMC10901482 | biostudies-literature

Chiral Hypervalent Iodine Catalysis Enables an Unusual Regiodivergent Intermolecular Olefin Aminooxygenation.

Project description:A novel iodide-catalyzed intermolecular aminooxygenation strategy is described here. Amide is used as the O- and N- source to probe for regiocontrol strategies. Notably, simple additives can be selectively introduced to achieve regiodivergent oxyamination processes for electronically activated alkenes while being regio-complementary for unactivated alkenes. Our preliminary data demonstrates that this regiocontrol strategy based on nucleophile can also be applied in asymmetric processes using chiral hypervalent iodine catalysis.

| S-EPMC8243328 | biostudies-literature

Simple, chemoselective, catalytic olefin isomerization.

Project description:Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.

| S-EPMC4277770 | biostudies-literature

Olefin Functionalization/Isomerization Enables Stereoselective Alkene Synthesis.

Project description:Despite tremendous efforts aimed at devising methods for stereoselective alkene synthesis, critical challenges are yet to be addressed. Direct access to a diverse range of 1aryl(boryl)-1-methyl-functionalized tri- and tetrasubstituted trans alkenes, entities that are prevalent in many important molecules of interest, through a catalytic manifold from readily available α-olefin substrates remains elusive. Here, we demonstrate that catalytic amounts of a nonprecious N-heterocyclic carbene-Ni(I) complex in conjunction with a sterically bulky base promote site- and trans-selective union of monosubstituted olefins with a wide array of electrophilic reagents to deliver tri- and tetrasubstituted alkenes in up to 92% yield and >98% regio- and stereoselectivity. The protocol is amenable to the preparation of carbon- and heteroatom-substituted C=C bonds, providing distinct advantages over existing transformations. Utility is highlighted through concise stereoselective synthesis of biologically active compounds.

| S-EPMC9431960 | biostudies-literature

Bis(Cyclic Alkyl Amino Carbene) Ruthenium Complexes: A Versatile, Highly Efficient Tool for Olefin Metathesis.

Project description:The state-of-the-art in olefin metathesis is application of N-heterocyclic carbene (NHC)-containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)-containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported.

| S-EPMC5299612 | biostudies-literature

Enantioselective olefin metathesis with cyclometalated ruthenium complexes.

Project description:The success of enantioselective olefin metathesis relies on the design of enantioenriched alkylidene complexes capable of transferring stereochemical information from the catalyst structure to the reactants. Cyclometalation of the NHC ligand has proven to be a successful strategy to incorporate stereogenic atoms into the catalyst structure. Enantioenriched complexes incorporating this design element catalyze highly Z- and enantioselective asymmetric ring opening/cross metathesis (AROCM) of norbornenes and cyclobutenes, and the difference in ring strain between these two substrates leads to different propagating species in the catalytic cycle. Asymmetric ring closing metathesis (ARCM) of a challenging class of prochiral trienes has also been achieved. The extent of reversibility and effect of reaction setup was also explored. Finally, promising levels of enantioselectivity in an unprecedented Z-selective asymmetric cross metathesis (ACM) of a prochiral 1,4-diene was demonstrated.

| S-EPMC4183615 | biostudies-other

Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis.

Project description:Olefin metathesis is now one of the most efficient ways to create new carbon-carbon bonds. While most efforts focused on the development of ever-more efficient catalysts, a particular attention has recently been devoted to developing latent metathesis catalysts, inactive species that need an external stimulus to become active. This furnishes an increased control over the reaction which is crucial for applications in materials science. Here, we report our work on the development of a new system to achieve visible-light-controlled metathesis by merging olefin metathesis and photoredox catalysis. The combination of a ruthenium metathesis catalyst bearing two N-heterocyclic carbenes with an oxidizing pyrylium photocatalyst affords excellent temporal and spatial resolution using only visible light as stimulus. Applications of this system in synthesis, as well as in polymer patterning and photolithography with spatially resolved ring-opening metathesis polymerization, are described.

| S-EPMC7097883 | 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