Browse
Submit Data
Databases
API
Help

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Base-Promoted C-C Bond Activation Enables Radical Allylation with Homoallylic Alcohols.

ABSTRACT: The Cα-Cβ bond in homoallylic alcohols can be activated under basic conditions, qualifying these nonstrained acyclic systems as radical allylation reagents. This reactivity is exemplified by photoinitiated (with visible light and/or blue LEDs) allylation of perfluoroalkyl and alkyl radicals generated from perfluoroalkyl iodides and alkylpyridinium salts, respectively, with homoallylic alcohols. C-radical addition to the double bond of the title reagents and subsequent base-promoted homolytic Cα-Cβ cleavage leads to the formation of the corresponding allylated products along with ketyl radicals that act as single electron reductants to sustain the chain reactions. Substrate scope is documented and the role of base in the C-C bond activation is studied by computation.

SUBMITTER: Lubbesmeyer M

PROVIDER: S-EPMC7021447 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Ruthenium-Catalyzed C-H Allylation of Alkenes with Allyl Alcohols via C-H Bond Activation in Aqueous Solution.

Project description:A robust Ru(II)-catalyzed C-H allylation of electron-deficient alkenes with allyl alcohols in aqueous solution is reported. This method provides a straightforward and efficient access to the synthetically useful 1,4-diene skeletons. With the assistance of the N-methoxycarbamoyl directing group, this allylation reaction features a broad substrate scope with good functional group tolerance, excellent regio- and stereoselectivity, absence of metal oxidants, water-tolerant solvents, and mild reaction conditions. The mechanistic studies indicate that the process of the reversible C-H bond ruthenation is assisted by acetate, and the rate-determining step is unlikely to be the step of C-H bond cleavage.

| S-EPMC7771258 | biostudies-literature

Triphosgene-amine base promoted chlorination of unactivated aliphatic alcohols.

Project description:Unactivated ?-branched primary and secondary aliphatic alcohols have been successfully transformed into their corresponding alkyl chlorides in high yields upon treatment with a mixture of triphosgene and pyridine in dichloromethane at reflux. These mild chlorination conditions are high yielding, stereospecific, and well tolerated by numerous sensitive functionalities. Furthermore, no nuisance waste products are generated in the course of the reactions.

| S-EPMC4153350 | biostudies-literature

Base-Promoted Radical Azofluoromethylation of Unactivated Alkenes.

Project description:The base-induced reaction of aryl diazonium salts with commercially available CF3SO2Na/CF2HSO2Na allows for the generation of the corresponding diazene radicals along with fluoromethyl radicals. The addition of fluoromethyl radicals to alkenes with subsequent diazene trapping provides the azofluoromethylation products in good to excellent yields. This metal-free method under mild reaction conditions has broad functional group compatibility and is applicable in the late-stage modification of various natural products and bioactive molecules.

| S-EPMC7328341 | biostudies-literature

Diastereoselective construction of functionalized homoallylic alcohols by Ni-catalyzed diboron-promoted coupling of dienes and aldehydes.

Project description:The nickel-catalyzed reaction of carbonyls and dienes was accomplished in a regio- and stereoselective fashion employing a stoichiometric amount of bis(pinacolato)diboron. This reductive coupling furnishes an allyl boronic ester as the reaction product, a compound which was readily converted to the derived allylic alcohol by oxidative workup.

| S-EPMC2676113 | biostudies-literature

Activation of alcohols with carbon dioxide: intermolecular allylation of weakly acidic pronucleophiles.

Project description:The direct coupling of allyl alcohols with nitroalkanes, nitriles, and aldehydes using catalytic Pd(PPh3)4 has been accomplished via activation of C-OH bonds with CO2. The in situ formation of carbonates from alcohols and CO2 facilitates oxidative addition to Pd to form reactive ?-allylpalladium intermediates. In addition, the formation of a strong base activates nucleophiles toward the reaction with the ?-allylpalladium electrophile. Overall, this atom economical reaction provides a new C-C bond without the use of an external base and generates water as the only byproduct.

| S-EPMC4136682 | biostudies-literature

Application of a High-Throughput Enantiomeric Excess Optical Assay Involving a Dynamic Covalent Assembly: Parallel Asymmetric Allylation and <i>Ee</i> Sensing of Homoallylic Alcohols.

Project description:Asymmetric Ir-catalyzed C-C coupling of primary alcohols with allyl-acetates, as described by Krische, to form chiral secondary homo-allylic alcohols were performed in parallel as a means to optimize the ee values thereof. Specifically, approximately 400 examples of this reaction were performed by varying the catalyst, added acids and bases, and starting reactants, to form 4-phenyl-1-butene-4-ol (1). The ee values for the transformations were determined in a high-throughput fashion using a 4-component assembly that creates a circular dichroism signal indicative of the extent of asymmetric induction. Further, a parallel and rapid quantitative TLC method measures the yield of each reaction, revealing which reactions give reliable ee values in the CD-based assay. Overall, the nearly 200 reactions whose ee values were determined could be quantitated in under two hours. Using a combination of the TLC method to measure yield with the CD-assay to measure ee values, several trends in reaction conditions were revealed. For example, it was found that the cyclometallated iridium catalyst modified by BINAP and m-nitro-p-cyano-benzoic acid delivered adduct 1 with the highest levels of enantiomeric enrichment (94%), whereas the corresponding SEGPHOS-modified catalyst gave a comparable yield but lower ee (91%). Most importantly, this study shows that supramolecular assemblies can report hundreds of ee values in a rapid and reliable fashion to analyze parallel synthesis routines.

| S-EPMC4800411 | biostudies-literature

Iodine-catalyzed prins cyclization of homoallylic alcohols and aldehydes.

Project description:The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. Anhydrous conditions and inert atmosphere are not required. The reaction of 2-(3,4-dihydronaphthalen-1-yl)propan-1-ol and 21 aldehydes (aliphatic and aromatic) in CH₂Cl₂ in the presence of 5 mol % of iodine gave 1,4,5,6-tetrahydro-2H-benzo[f]isochromenes in 54%-86% yield. Under similar conditions, the Prins cyclization of six alcohols containing an endocyclic double bond (primary, secondary, or tertiary) led to dihydropyrans in 52%-91% yield. The acyclic homoallylic alcohols gave 4-iodo-tetrahydropyran in 29%-41% yield in the presence of 50 mol % of iodine. This type of substrate is the main limitation of the methodology. The relative configuration of the products was assigned by NMR and X-ray analysis. The mechanism and the ratio of the products are discussed, based on DFT calculations.

| S-EPMC6269844 | biostudies-literature

A multicomponent approach for the preparation of homoallylic alcohols.

Project description:Here we report the in situ generation of transient allylic boronic species, by reacting TMSCHN2 and E-vinyl boronic acids, followed by their subsequent trapping with aldehydes as electrophiles to yield homoallylic alcohols. This metal-free reaction was initially discovered by the use of a flow chemistry approach to generate a variety of homoallylic alcohols in a straightforward fashion and then transferred to a batch protocol.

| S-EPMC5134730 | biostudies-literature

Catalytic enantioselective epoxidation of tertiary allylic and homoallylic alcohols.

Project description:An efficient and versatile method for the enantioselective epoxidation of both tertiary allylic and homoallylic alcohols catalyzed by Hf(IV)-bishydroxamic acid (BHA) complexes is described. Asymmetric epoxidation, kinetic resolution, and desymmetrization have been developed, demonstrating the flexible nature of the Hf(IV)-BHA system. This is the first report in which these substrates were obtained with enantioselectivities of up to 99%.

| S-EPMC3625140 | biostudies-literature

Catalytic Lewis Base Additive Enables Selective Copper-Catalyzed Borylative α-C-H Allylation of Alicyclic Amines.

Project description:Functionalized alicyclic amines are important building blocks for the synthesis of bioactive natural compounds and drugs. Existing methods of functionalization are typically limited to the synthesis of protected amines or the use of highly basic organometallic reagents that can compromise functional group tolerance. Here, we report a novel approach that enables the transformation of O-benzoyl hydroxylamines into α-functionalized cyclic secondary amines by means of a copper-catalyzed regio-, stereo-, and chemoselective coupling with allenes and bis(pinacolato)diboron. A key feature of the present transformation is the use of a catalytic Lewis base additive which inhibits the competing C-N bond forming reaction between the catalytically generated boron-substituted allylcopper intermediate with the O-benzoyl hydroxylamine, thus enabling in situ transformation of the latter into an alicyclic imine which undergoes selective C-C bond formation with the allylcopper species.

| S-EPMC9460777 | 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