Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Preparation and wittig reactions of organotrifluoroborato phosphonium ylides.

ABSTRACT: [reaction: see text] Potassium [(trifluoroboratophenyl)methyl]triphenylphosphonium chlorides have been prepared from the corresponding benzyl chlorides and PPh3. In the presence of 1.2 equiv of K2CO3 and various aldehydes, these mixed salts are easily converted to the corresponding unsaturated organotrifluoroborates via the intermediate phosphorus ylides. A protocol for a one-pot transformation has also been developed.

SUBMITTER: Molander GA

PROVIDER: S-EPMC2556880 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Preparation and wittig reactions of organotrifluoroborato phosphonium ylides.

Molander Gary A GA Ham Jungyeob J Canturk Belgin B

Organic letters 20070206 5

[reaction: see text] Potassium [(trifluoroboratophenyl)methyl]triphenylphosphonium chlorides have been prepared from the corresponding benzyl chlorides and PPh3. In the presence of 1.2 equiv of K2CO3 and various aldehydes, these mixed salts are easily converted to the corresponding unsaturated organotrifluoroborates via the intermediate phosphorus ylides. A protocol for a one-pot transformation has also been developed. ...[more]

PMID: 17279765

Similar Datasets

Basic Phosphonium Ionic Liquids as Wittig Reagents.

Project description:The possibility of designing a solvent/reagent for Wittig reactions from basic phosphonium salts is explored theoretically. In the suggested R4P+PhO- and Ph3PR+PhO- ionic liquids (ILs), the phenolate anion is prone to remove the α-proton from the alkyl chains, forming a phosphorous ylide. Significant hydrogen bonding between the oxygen atoms of the anions and α-hydrogen atoms of the cations were found by molecular dynamics simulations of these substances; therefore, proton transfer between the two ions is inherently supported by the structure of the liquid as well. The subsequent steps of the Wittig reaction from the phosphorous ylide were also found to be energetically possible. The mesoscopic structure of these materials exhibits a significant segregation into polar and nonpolar domains, which may also allow an easy dissolution of the substrates. The formation of a pentacoordinated phosphorous derivative through P-O bond formation was found to be also possible in the gas phase for both kind of compounds. Accordingly, having such basic anions in phosphonium-based ILs may produce such a neutral and therefore volatile species, which may hold further significant applications for these solvents in ion-exchange and separation techniques and in synthesis.

| S-EPMC6641186 | biostudies-literature

Further Studies on the Pyrolytic Domino Cyclization of Stabilized Phosphonium Ylides Bearing an Ortho-Aminophenyl Group.

Project description:Four new, stabilized phosphonium ylides containing a 2-(benzyl(methyl)amino)phenyl group have been prepared and characterized and are found, upon pyrolysis under gas-phase flow conditions, to lose Ph?PO and benzyl radicals to afford new heterocyclic products resulting from domino cyclization of both C- and N-centered radicals. Most products arise from processes of the former type and have quinoline, phenanthridine, or ring-fused phenanthridine structures, while in one case, a process of the latter type leads to a benzocarbazole product. The X-ray structure of a 2-(methyl(tosyl)amino)phenyl ylide is also reported.

| S-EPMC6225108 | biostudies-literature

Equilibrium between a vinylogous ylide and a phosphonium dienolate zwitterion: vinylogous Wittig olefination versus vinylogous aldol-type reaction.

Project description:This paper describes the equilibrium established between a phosphonium dienolate zwitterion and a vinylogous phosphorus ylide, and their reactions with aldehydes. The reactions between ethyl 2-methyl-2,3-butadienoate and various aldehydes occur through either a phosphonium dienolate or a vinylogous ylide intermediate, depending on the presence/absence of a Lewis acid and the nature of the phosphine. We observed a rare vinylogous Wittig olefination from the reaction between ethyl 2-methyl-2,3-butadienoate and an electron-deficient aromatic aldehyde in the presence of a stoichiometric amount of an electron-deficient triarylphosphine and a catalytic amount of a Lewis acid (e.g., BF(3)·Et(2)O). On the other hand, the use of triphenylphosphine, in the absence of a Lewis acid, facilitated vinylogous aldol addition, accompanied by a rare 1,2-aryl phosphorus-to-carbon migration.

| S-EPMC3043383 | biostudies-literature

Enantioselective S-H Insertion Reactions of α-Carbonyl Sulfoxonium Ylides.

Project description:The first example of enantioselective S-H insertion reactions of sulfoxonium ylides is reported. Under the influence of thiourea catalysis, excellent levels of enantiocontrol (up to 95 % ee) and yields (up to 97 %) are achieved for 31 examples in S-H insertion reactions of aryl thiols and α-carbonyl sulfoxonium ylides.

| S-EPMC7606806 | biostudies-literature

Unusually reactive and selective carbonyl ylides for three-component cycloaddition reactions.

Project description:Conditions are described for the Rh-catalyzed formation of highly functionalized dihydro- and tetrahydrofuran products via three-component reactions of aldehydes, alpha-alkyl-alpha-diazoesters, and dipolarophiles. The alkyl-substituted carbonyl ylides that are generated in this fashion are highly reactive in cycloaddition reactions and display a scope of reactivity that is much broader than the three-component reactions of carbonyl ylides derived from ethyl diazoacetate or alpha-aryl-alpha-diazoesters. The reactions of alkyl-substituted carbonyl ylides proceed with high regioselectivity and diastereoselectivity that are rationalized in terms of an asynchronous, endo-selective transition state.

| S-EPMC2659807 | biostudies-literature

Difluoromethanesulfonyl hypervalent iodonium ylides for electrophilic difluoromethylthiolation reactions under copper catalysis.

Project description:Difluoromethanesulfonyl hypervalent iodonium ylides 2 were developed as electrophilic difluoromethylthiolation reagents for a wide range of nucleophiles. Enamines, indoles, ?-keto esters, silyl enol ethers and pyrroles were effectively reacted with 2 affording desired difluoromethylthio (SCF2H)-substituted compounds in good to high yields under copper catalysis. The reaction of allyl alcohols with 2 under the same conditions provided difluoromethylsulfinyl (S(O)CF2H) products in good yields. The difluoromethylthiolation of enamines is particularly effective with wide generality, thus the enamine method was nicely extended to the synthesis of a series of difluoromethythiolated cyclic and acyclic ?-keto esters, 1,3-diketones, pyrazole and pyrimidine derivatives by a consecutive, two-step one-pot reaction using 2.

| S-EPMC4892452 | biostudies-literature

Sometimes, the Least Demanding Solution Is the Most Suitable: A Careful Survey of NMR Spectra of a Phosphonium Salt Accounted for Its "Unusual Wittig Reaction".

Project description:Careful product analysis in combination with appropriate supporting experiments unambiguously proves that in contrast to what was previously reported, generation of the phosphonium salt from a β-cyclocitral-derived allylic alcohol and PPh3HBr takes place via a proton-driven elimination/addition path.

| S-EPMC6644793 | biostudies-literature

Facile Pyridine S N Ar Reactions via N-Phosphonium-Pyridinium Intermediates.

Project description:Here we report that N-phosphonium pyridinium intermediates are unusually reactive for pyridine S N Ar reactions. Specifically, forming phosphonium salts from halopyridines typically requires elevated temperatures and Lewis acid additives. The alternative activation mode described in this paper permits C-P bond formation to occur at ambient temperatures in many cases, and functions across a broad range of substrates.

| S-EPMC8081384 | biostudies-literature

A novel one-pot green synthesis of dispirooxindolo-pyrrolidines via 1,3-dipolar cycloaddition reactions of azomethine ylides.

Project description:A facile synthesis of dispirooxindolopyrrolidines has been accomplished via a one-pot three component 1,3-dipolar cycloaddition reaction. The reaction of azomethine ylides generated in situ from L-phenylalanine and substituted isatins with a series of unusual (E)-2-oxoindolino-3-ylidene acetophenone dipolarophiles in the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]BF4, furnished the cycloadducts in good yields, with the regioisomers 5a-f being obtained with high selectivity. Furthermore, the recyclability of [bmim]BF4, up to five times, was also investigated.

| S-EPMC6272743 | biostudies-literature

Preparation and Diels-Alder reactions of 1'-heterosubsituted vinylimidazoles.

Project description:A Diels-Alder/rearrangement sequence has been pursued in our lab en route to a number of oroidin dimers. In order to access the fully substituted core of these molecules, 1',2'-disubstituted 4-vinylimidazoles were required as dienes. The preparation of a series of a 4-vinylimidazoles containing substituents on the vinyl moiety via hydroalumination/electrophilic trapping or hydrosilylation are described. These derivatives undergo Diels-Alder reactions with N-phenylmaleimide to provide the tetrahydrobenzimidazole derivatives. The cycloadducts derived from halosubstituted systems generally undergo elimination, leading to the corresponding dihydrobenzimidazole, whereas the silyl and stannyl derivatives provide the corresponding 4-substituted tetrahydrobenzimidazole.

| S-EPMC4484863 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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