Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric bisboranes as bidentate catalysts for carbonyl substrates.

ABSTRACT: A new class of C(2) symmetric bisoxazaborolidinone compounds is described which exhibits bidentate binding to carbonyl substrates. Using the Diels-Alder reaction as a model system, the catalytic activity of these bis-Lewis acids is probed. Reaction rates and selectivities are observed that are higher than the corresponding mono-Lewis acids. This novel system offers a potentially powerful new approach to asymmetric Lewis acid catalysis.

SUBMITTER: Rodriguez AA

PROVIDER: S-EPMC2662717 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric bisboranes as bidentate catalysts for carbonyl substrates.

Rodriguez Andrew A AA Zhao Carrie C Shea Kenneth J KJ

Organic letters 20090201 3

A new class of C(2) symmetric bisoxazaborolidinone compounds is described which exhibits bidentate binding to carbonyl substrates. Using the Diels-Alder reaction as a model system, the catalytic activity of these bis-Lewis acids is probed. Reaction rates and selectivities are observed that are higher than the corresponding mono-Lewis acids. This novel system offers a potentially powerful new approach to asymmetric Lewis acid catalysis. ...[more]

PMID: 19175350

Similar Datasets

N, N’-bidentate ligand anchored palladium catalysts on MOFs for efficient Heck reaction

Project description: Not available

| S-EPMC11344049 | biostudies-literature

Latent ruthenium-indenylidene catalysts bearing a N-heterocyclic carbene and a bidentate picolinate ligand.

Project description:A silver-free methodology was developed for the synthesis of unprecedented N-heterocyclic carbene ruthenium indenylidene complexes bearing a bidentate picolinate ligand. The highly stable (SIPr)(picolinate)RuCl(indenylidene) complex 4a (SIPr = 1,3-bis(2-6-diisopropylphenyl)imidazolidin-2-ylidene) demonstrated excellent latent behaviour in ring closing metathesis (RCM) reaction and could be activated in the presence of a Brønsted acid. The versatility of the catalyst 4a was subsequently demonstrated in RCM, cross-metathesis (CM) and enyne metathesis reactions.

| S-EPMC4578404 | biostudies-literature

Electrochemical carbonyl reduction on single-site M-N-C catalysts.

Project description:Electrochemical conversion of organic compounds holds promise for advancing sustainable synthesis and catalysis. This study explored electrochemical carbonyl hydrogenation on single-site M-N-C (Metal Nitrogen-doped Carbon) catalysts using formaldehyde, acetaldehyde, and acetone as model reactants. We strive to correlate and understand the selectivity dependence on the nature of the metal centers. Density Functional Theory calculations revealed similar binding energetics for carbonyl groups through oxygen-down or carbon-down adsorption due to oxygen and carbon scaling. Fe-N-C exhibited specific oxyphilicity and could selectively reduce aldehydes to hydrocarbons. By contrast, the carbophilic Co-N-C selectively converted acetaldehyde and acetone to ethanol and 2-propanol, respectively. We claim that the oxyphilicity of the active sites and consequent adsorption geometry (oxygen-down vs. carbon-down) are crucial in controlling product selectivity. These findings offer mechanistic insights into electrochemical carbonyl hydrogenation and can guide the development of efficient and sustainable electrocatalytic valorization of biomass-derived compounds.

| S-EPMC10542751 | biostudies-literature

Photoisomerization and thermal isomerization of ruthenium aqua complexes with chloro-substituted asymmetric bidentate ligands.

Project description:A series of ruthenium complexes with chloro-substituted bidentate ligands, proximal-[Ru(tpy)(Cl-pyqu)L] n+ [n = 1 for L = Cl, and n = 2 for L = OH2, tpy = 2,2';6',2''-terpyridine, pyqu = 2-(2'-pyridyl)quinoline] were synthesized and their reversible photoisomerizations and thermal isomerizations were investigated experimentally. The crystal structures of the complexes indicated that introduction of a chloro substituent at the 4- or 4'-position of the pyqu ligand did not change the structure around the metal center from that of the non-substituted complex, proximal-[Ru(tpy)(pyqu)L] n+. In contrast, the 6'-substituted complexes had sterically hindered environments around the metal center. The ruthenium aqua complexes showed reversible photoisomerization between the proximal and distal isomers. The quantum yield for photoisomerization of the 6'-substituted ruthenium aqua complex was almost twice as large as those of the other derivatives. This is explained by weakening of the ligand field on the ruthenium center by introduction of a chloro substituent at the 6'-position. Thermal back isomerization from the distal isomer to the proximal one was observed for the 6'-substituted complex, but such reactions were not observed for the other derivatives. The steric hindrance in the 6'-substituted aqua complex enhanced both thermal isomerization and photoisomerization.

| S-EPMC9059708 | biostudies-literature

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization.

Project description:A full account of our efforts toward an asymmetric redox bicycloisomerization reaction is presented in this article. Cyclopentadienylruthenium (CpRu) complexes containing tethered chiral sulfoxides were synthesized via an oxidative [3 + 2] cycloaddition reaction between an alkyne and an allylruthenium complex. Sulfoxide complex 1 containing a p-anisole moiety on its sulfoxide proved to be the most efficient and selective catalyst for the asymmetric redox bicycloisomerization of 1,6- and 1,7-enynes. This complex was used to synthesize a broad array of [3.1.0] and [4.1.0] bicycles. Sulfonamide- and phosphoramidate-containing products could be deprotected under reducing conditions. Catalysis performed with enantiomerically enriched propargyl alcohols revealed a matched/mismatched effect that was strongly dependent on the nature of the solvent.

| S-EPMC4979649 | biostudies-literature

Profluorescent substrates for the screening of olefin metathesis catalysts.

Project description:Herein we report on a 96-well plate assay based on the fluorescence resulting from the ring-closing metathesis of two profluorophoric substrates. To demonstrate the validity of the approach, four commercially available ruthenium-metathesis catalysts were evaluated in six different solvents. The results from the fluorescent assay agree well with HPLC conversions, validating the usefulness of the approach.

| S-EPMC4660973 | biostudies-literature

Asymmetric C-H functionalization of cyclopropanes using an isoleucine-NH<sub>2</sub> bidentate directing group.

Project description:The systematic investigation of substrate-bound α-amino acid auxiliaries has resulted in catalytic asymmetric C-H functionalization of cyclopropanes enabled by amino acid amides as chiral bidentate directing groups. The use of an Ile-NH2 auxiliary embedded in the substrate provided excellent levels of asymmetric induction (diastereomeric ratio of up to 72 : 1) in the Pd(ii)-catalyzed β-methylene C(sp3)-H bond activation of cyclopropanes and cross-coupling with aryl iodides.

| S-EPMC5659170 | biostudies-literature

Manganese(I)-Catalyzed Asymmetric Hydrophosphination of α,β-Unsaturated Carbonyl Derivatives.

Project description:Here we report catalytic asymmetric hydrophosphination of α,β-unsaturated carbonyl derivatives using a chiral Mn(I) complex as a catalyst. Through H-P bond activation, various phosphine-containing chiral products can be accessed via hydrophosphination of various ketone-, ester-, and carboxamide-based Michael acceptors.

| S-EPMC10028696 | biostudies-literature

Asymmetric cyclopropanation of chalcones using chiral phase-transfer catalysts.

Project description:The first phase-transfer catalyzed cyclopropanation reaction of chalcones using bromomalonates as the nucleophiles in a Michael Initiated Ring Closing reaction (MIRC) was developed. Key to success was the use of a free OH-containing cinchona alkaloid ammonium salt catalyst and carefully optimized liquid/liquid reaction conditions. The reaction performed well for electron neutral and electron deficient chalcones giving the products in yields up to 98% and with enantiomeric ratios up to 91:9.

| S-EPMC3878557 | biostudies-literature

Zirconium Bis(Amido) Catalysts for Asymmetric Intramolecular Alkene Hydroamination.

Project description:In situ combination of diphosphinic amides and Zr(NMe(2))(4) results in the formation of chiral zirconium bis(amido) complexes. The complexes are competent catalysts for intramolecular asymmetric alkene hydroamintion, providing piperidines and pyrrolidines in up to 80% ee and high yield. This system utilizes an inexpensive zirconium precatalyst and readily prepared ligands and is the first asymmetric alkene hydroamination catalyst based upon a neutral zirconium bis(amido) complex.

| S-EPMC2600731 | 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