Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Arylboronic Acid Catalyzed C-Alkylation and Allylation Reactions Using Benzylic Alcohols.

ABSTRACT: The arylboronic acid catalyzed dehydrative C-alkylation of 1,3-diketones and 1,3-ketoesters using secondary benzylic alcohols as the electrophile is reported, forming new C-C bonds (19 examples, up to 98% yield) with the release of water as the only byproduct. The process is also applicable to the allylation of benzylic alcohols using allyltrimethylsilane as the nucleophile (12 examples, up to 96% yield).

SUBMITTER: Estopina-Duran S

PROVIDER: S-EPMC8155392 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Arylboronic Acid Catalyzed C-Alkylation and Allylation Reactions Using Benzylic Alcohols.

Estopiñá-Durán Susana S Mclean Euan B EB Donnelly Liam J LJ Hockin Bryony M BM Taylor James E JE

Organic letters 20200922 19

The arylboronic acid catalyzed dehydrative C-alkylation of 1,3-diketones and 1,3-ketoesters using secondary benzylic alcohols as the electrophile is reported, forming new C-C bonds (19 examples, up to 98% yield) with the release of water as the only byproduct. The process is also applicable to the allylation of benzylic alcohols using allyltrimethylsilane as the nucleophile (12 examples, up to 96% yield). ...[more]

PMID: 32959662

Similar Datasets

Arylboronic Acid-Catalyzed Racemization of Secondary and Tertiary Alcohols.

Project description:The use of 2-carboxyphenylboronic acid (5 mol %) and oxalic acid (10 mol %) with 2-butanone as a solvent for the racemization of a range of enantiomerically pure secondary and tertiary alcohols is demonstrated. The process is postulated to proceed via reversible Brønsted acid-catalyzed C-O bond cleavage through an achiral carbocation intermediate.

| S-EPMC9552221 | biostudies-literature

Green, Palladium-Catalyzed Synthesis of Benzylic H-phosphinates from Hypophosphorous Acid and Benzylic Alcohols.

Project description:Benzylic alcohols cross-couple directly with concentrated H(3)PO(2) using Pd/xantphos (1 or 2 mol-%). Depending on the substrate, DMF at 110°C, or t-AmOH at reflux with a Dean-Stark trap, can be used. A broad range of benzylic alcohols reacted successfully in moderate to good yields. The preparation of other organophosphorus compounds (phosphinic and phosphonic acids) is also demonstrated.Asymmetric reaction with (R)-1-(2-naphthyl)ethanol provided the corresponding H-phosphinic acid in 77% ee. The methodology provides a green, PCl(3)-free, entry into benzylic-H-phosphinic acids.

| S-EPMC3551600 | biostudies-literature

Homogeneous Sc(OTf)3-Catalyzed Direct Allylation Reactions of General Alcohols with Allylsilanes.

Project description:Homogeneous Sc(OTf)3 used in nitromethane showed excellent catalytic activity for the direct allylation reactions of general alcohols including benzylic, propargylic, allylic, and some aliphatic alcohols with allyltrimethylsilane under mild and neutral reaction conditions. Metal-free β-silyl-substituted carbocations are intermediates generated by the highly oxophilic Sc(OTf)3-assisted rapid removal of a hydroxyl group in alcohols, which is supported by the result that allylation of (R)-1-(naphthalen-2-yl)ethan-1-ol with allytrimethylsilanes using the Sc(OTf)3 catalyst combined with (R)- or (S)-[1,1'-binaphthalene]-2,2'-diol ligands gave only racemic 2-(pent-4-en-2-yl)naphthalene in quantitative yield. The present study resolves the argument about the uncertain catalytic activity of Sc(OTf)3.

| S-EPMC6643996 | biostudies-literature

Visible-Light Photoredox-Catalyzed Amidation of Benzylic Alcohols.

Project description:A new photocatalyzed route to amides from alcohols and amines mediated by visible light is presented. The reaction is carried out in ethyl acetate as a solvent. Ethyl acetate can be defined a green and bio-based solvent. The starting materials such as the energy source are easily available, stable, and inexpensive. The reaction has shown to be general and high yielding.

| S-EPMC8009506 | biostudies-literature

Organic photoredox-catalyzed unimolecular PCET of benzylic alcohols.

Project description:Proton-coupled electron transfer (PCET) is a crucial chemical process involving the simultaneous or sequential transfer of protons and electrons, playing a vital role in biological processes and energy conversion technologies. This study investigates the use of an organic photoredox catalyst to facilitate a unimolecular PCET process for the generation of alkyl radicals from benzylic alcohols, with a particular focus on alcohols containing electron-rich arene units. By employing a benzophenone derivative as the catalyst, the reaction proceeds efficiently under photoirradiation, achieving significant yields without the need for a Brønsted base. The findings highlight the potential of this unimolecular PCET mechanism to streamline radical generation in organic synthesis, offering a more efficient and flexible alternative to conventional methods.

| S-EPMC11740339 | biostudies-literature

Manganese-Catalyzed α-Alkylation of Ketones, Esters, and Amides Using Alcohols.

Project description:Herein we report the manganese-catalyzed C-C bond-forming reactions via α-alkylation of ketones, amides, and esters, using primary alcohols. β-Alkylation of secondary alcohols by primary alcohols to obtain α-alkylated ketones is also reported. The reactions are catalyzed by a ( i Pr-PNP)Mn(H)(CO)2 pincer complex under mild conditions in the presence of (catalytic) base liberating water (and H2 in the case of secondary alcohol alkylation) as the sole byproduct.

| S-EPMC6466737 | biostudies-literature

Chromium-Catalyzed Alkylation of Amines by Alcohols.

Project description:The alkylation of amines by alcohols is a broadly applicable, sustainable, and selective method for the synthesis of alkyl amines, which are important bulk and fine chemicals, pharmaceuticals, and agrochemicals. We show that Cr complexes can catalyze this C-N bond formation reaction. We synthesized and isolated 35 examples of alkylated amines, including 13 previously undisclosed products, and the use of amino alcohols as alkylating agents was demonstrated. The catalyst tolerates numerous functional groups, including hydrogenation-sensitive examples. Compared to many other alcohol-based amine alkylation methods, where a stoichiometric amount of base is required, our Cr-based catalyst system gives yields higher than 90 % for various alkyl amines with a catalytic amount of base. Our study indicates that Cr complexes can catalyze borrowing hydrogen or hydrogen autotransfer reactions and could thus be an alternative to Fe, Co, and Mn, or noble metals in (de)hydrogenation catalysis.

| S-EPMC7384194 | biostudies-literature

Iron-Catalyzed Selective Etherification and Transetherification Reactions Using Alcohols.

Project description:Simple and readily available iron(III) triflate turned out to be a cheap, environmentally benign, and efficient catalyst for the direct etherification of alcohols. The use of ammonium chloride as an additive (5 mol %, 1 equiv relative to catalyst) suppressed the side reactions completely and ensured the selective ether formation even on challenging substrates containing electron-donating substituents. This method allows the selective synthesis of symmetrical ethers from benzylic secondary alcohols and unsymmetrical ethers directly from secondary and primary alcohols. Moreover, transetherification of symmetrical ethers using primary alcohols is attained. The reaction progress of symmetrical ether and unsymmetrical ether formation followed zero-order and first-order kinetics, respectively. Electron paramagnetic resonance (EPR) measurements of the reaction mixture and simple iron(III) triflate clearly indicated that oxidation state of the metal center remains same throughout the catalysis. Mechanistic studies confirmed that the unsymmetrical ether formation occurs via the in situ formed symmetrical ethers.

| S-EPMC6641510 | biostudies-literature

Palladium-catalyzed regio-, diastereo-, and enantioselective benzylic allylation of 2-substituted pyridines.

Project description:We report a new method for the highly regio-, diastereo-, and enantioselective palladium-catalyzed allylic alkylation of 2-substituted pyridines that allows for the formation of homoallylic stereocenters containing alkyl, aryl, heteroaryl, and nitrogen substituents. When the reaction is conducted with asymmetric acyclic electrophiles, both linear and branched products may be obtained exclusively by selecting the appropriate regioisomeric starting material and ligand, an example of the "memory effect." Deuterium-labeling studies reveal that though no such phenomenon occurs with racemic cyclic electrophiles, the chiral ligand employed reacts kinetically faster with the enantiomer of the substrate for which it is "matched" and yet eventually converts all "mismatched" substrate to product.

| S-EPMC3235048 | biostudies-literature

Palladium-Catalyzed Allylation/Benzylation of H-Phosphinate Esters with Alcohols.

Project description:The Pd-catalyzed direct alkylation of H-phosphinic acids and hypophosphorous acid with allylic/benzylic alcohols has been described previously. Here, the extension of this methodology to H-phosphinate esters is presented. The new reaction appears general, although its scope is narrower than with the acids, and its mechanism is likely different. Various alcohols are examined in their reaction with phosphinylidene compounds R¹R²P(O)H.

| S-EPMC6273960 | biostudies-literature