Browse
Submit Data
Databases
API
Help

Dataset Information

25 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Catalytic asymmetric stetter reaction onto vinylphosphine oxides and vinylphosphonates.

ABSTRACT: An intramolecular Stetter reaction of vinylphosphine oxides and vinylphosphonates has been developed. Treatment of an aldehyde with a nucleophilic N-heterocyclic carbene catalyst allows for addition of an acyl anion equivalent into a vinylphosphine oxide or vinylphosphonate Michael acceptor in yields up to 99% and ee values up to 96%.

SUBMITTER: Cullen SC

PROVIDER: S-EPMC2746454 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Catalytic asymmetric stetter reaction onto vinylphosphine oxides and vinylphosphonates.

Cullen Steven C SC Rovis Tomislav T

Organic letters 20080613 14

An intramolecular Stetter reaction of vinylphosphine oxides and vinylphosphonates has been developed. Treatment of an aldehyde with a nucleophilic N-heterocyclic carbene catalyst allows for addition of an acyl anion equivalent into a vinylphosphine oxide or vinylphosphonate Michael acceptor in yields up to 99% and ee values up to 96%. ...[more]

PMID: 18549233

Similar Datasets

Catalytic asymmetric intermolecular Stetter reaction of glyoxamides with alkylidenemalonates.

Project description:An asymmetric intermolecular Stetter reaction of glyoxamide and alkylidenemalonates has been developed. Catalyzed by a novel N-heterocyclic carbene, the Stetter adducts are formed in good yield and excellent enantioselectivity. The presence of a sensitive epimerizable stereocenter is tolerated under these mildly basic reaction conditions if a bulky amine base is used. The products may be further elaborated to provide synthetically useful intermediates.

| S-EPMC2684863 | biostudies-literature

Catalytic asymmetric intermolecular Stetter reaction of enals with nitroalkenes: enhancement of catalytic efficiency through bifunctional additives.

Project description:An asymmetric intermolecular Stetter reaction of enals with nitroalkenes catalyzed by chiral N-heterocyclic carbenes has been developed. The reaction rate and efficiency are profoundly impacted by the presence of catechol. The reaction proceeds with high selectivities and affords good yields of the Stetter product. Internal redox products were not observed despite of the protic conditions. The impact of catechol has been found to be general, facilitating far lower catalyst loadings than were previously achievable.

| S-EPMC3147302 | biostudies-literature

Catalytic asymmetric intermolecular stetter reaction of heterocyclic aldehydes with nitroalkenes: backbone fluorination improves selectivity.

Project description:The catalytic asymmetric intermolecular Stetter reaction of heterocyclic aldehydes and nitroalkenes has been developed. We have identified a strong stereoelectronic effect on catalyst structure when a fluorine substituent is placed in the backbone. X-ray structure analysis provides evidence that hyperconjugative effects are responsible for a change in conformation in the azolium precatalyst. This new N-heterocyclic carbene precursor bearing fluorine substitution in the backbone results in significantly improved enantioselectivities across a range of substrates.

| S-EPMC2747345 | biostudies-literature

Multicatalytic, asymmetric Michael/Stetter reaction of salicylaldehydes and activated alkynes.

Project description:We report the development of a multicatalytic, one-pot, asymmetric Michael/Stetter reaction between salicylaldehydes and electron-deficient alkynes. The cascade proceeds via amine-mediated Michael addition followed by an N-heterocyclic carbene-promoted intramolecular Stetter reaction. A variety of salicylaldehydes, doubly activated alkynes, and terminal, electrophilic allenes participate in a one-step or two-step protocol to give a variety of benzofuranone products in moderate to good yields and good to excellent enantioselectivities. The origin of enantioselectivity in the reaction is also explored; E/Z geometry of the reaction intermediate as well as the presence of catalytic amounts of catechol additive are found to influence reaction enantioselectivity.

| S-EPMC2996425 | biostudies-other

Scope of the asymmetric intramolecular stetter reaction catalyzed by chiral nucleophilic triazolinylidene carbenes.

Project description:A highly enantioselective intramolecular Stetter reaction of aromatic and aliphatic aldehydes tethered to different Michael acceptors has been developed. Two triazolium scaffolds have been identified that catalyze the intramolecular Stetter reaction with good reactivity and enantioselectivity. The substrate scope has been examined and found to be broad; both electron-rich and -poor aromatic aldehydes undergo cyclization in high yield and enantioselectivity. The tether can include oxygen, sulfur, nitrogen, and carbon linkers with no detrimental effects. In addition, the incorporation of various tethered Michael acceptors includes amides, esters, thioesters, ketones, aldehydes, and nitriles. The catalyst loading may be reduced to 3 mol % without significantly affecting the reactivity or selectivity of the reaction.

| S-EPMC4222522 | biostudies-literature

Asymmetric synthesis of hydrobenzofuranones via desymmetrization of cyclohexadienones using the intramolecular Stetter reaction.

Project description:Dearomatization of phenols followed by oxidation affords cyclohexadienyloxyacetaldehydes, which produce hydrobenzofuranones via asymmetric intramolecular Stetter reaction in good to excellent yield. Quaternary as well as up to three contiguous stereocenters may be formed in good to excellent enantioselectivities and high diastereoselectivities.

| S-EPMC2701296 | biostudies-literature

Enantioselective Synthesis of Hydrobenzofuranones Using an Asymmetric Desymmetrizing Intramolecular Stetter Reaction of Cyclohexadienones.

Project description:A series of cyclohexadienones were synthesized by dearomatization of phenols followed by Dess-Martin oxidation. Asymmetric intramolecular Stetter reactions of these substrates provide hydrobenzofuranones in good to excellent yields and excellent stereoselectivities. Up to three stereocenters as well as quaternary stereocenter are formed from polysubstituted substrates. A scale up experiment demonstrates the utility of this transformation.

| S-EPMC2709411 | biostudies-literature

Quantum mechanical investigation of the effect of catalyst fluorination in the intermolecular asymmetric Stetter reaction.

Project description:The asymmetric intermolecular Stetter reaction was investigated using the B3LYP and M06-2X functionals. Fluorination of a triazolium bicyclic catalyst had been found to significantly influence reaction yields and enantiomeric ratios. Computations indicate that the improved reactivity of the fluorinated catalyst is due to better electrostatic interactions between the nitroalkene and catalyst. Computational investigations of preferred conformations of the ground state catalyst and acyl anion equivalent, and the transition structures leading to both enantiomers of the products, are reported.

| S-EPMC3143204 | biostudies-literature

The Catalytic Asymmetric Intermolecular Prins Reaction.

Project description:Despite their significant potential, catalytic asymmetric reactions of olefins with formaldehyde are rare and metal-free approaches have not been previously disclosed. Here we describe an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde to form 1,3-dioxanes, using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts. Isotope labeling experiments and computations suggest a concerted, highly asynchronous addition of an acid-activated formaldehyde oligomer to the olefin. The enantioenriched 1,3-dioxanes can be transformed into the corresponding optically active 1,3-diols, which are valuable synthetic building blocks.

| S-EPMC8679094 | biostudies-literature

A catalytic asymmetric vinylogous Mukaiyama aldol reaction.

Project description:A vinylogous Mukaiyama aldol reaction, conducted using 10 mol % of a BITIP catalyst and B(OMe)3 as an additive, effects an enantioselective four-carbon chain extension to give versatile E-alpha,beta-unsaturated thiol esters.

| S-EPMC2516376 | 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