Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cu-catalyzed enantioselective synthesis of tertiary benzylic copper complexes and their in situ addition to carbonyl compounds.

ABSTRACT: Catalytic chemo- and enantioselective generation of tertiary benzylic copper complexes from Cu-B(pin) (pin = pinacolato) additions to 1,1-disubstituted alkenes followed by in situ reactions with ketones and carboxylic acid phenol esters to construct multifunctional alkylboron compounds that contain quaternary stereogenic centers is presented. The method is distinguished by the unprecedented reaction mode of tertiary benzylic Cu complexes, allowing reaction with a wide range of carbonyl electrophiles in good yields and with high chemo-, site-, diastereo- and enantioselectivity. The catalytic protocol was performed with easily accessible chiral ligands and copper salts at ambient temperature. Functionalization of multifunctional alkylboron products provides useful building blocks that are otherwise difficult to access.

SUBMITTER: Cheng F

PROVIDER: S-EPMC5989696 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Cu-catalyzed enantioselective synthesis of tertiary benzylic copper complexes and their <i>in situ</i> addition to carbonyl compounds.

Cheng Fengchang F Lu Wenxin W Huang Wei W Wen Lu L Li Mingfeng M Meng Fanke F

Chemical science 20180430 22

Catalytic chemo- and enantioselective generation of tertiary benzylic copper complexes from Cu-B(pin) (pin = pinacolato) additions to 1,1-disubstituted alkenes followed by <i>in situ</i> reactions with ketones and carboxylic acid phenol esters to construct multifunctional alkylboron compounds that contain quaternary stereogenic centers is presented. The method is distinguished by the unprecedented reaction mode of tertiary benzylic Cu complexes, allowing reaction with a wide range of carbonyl el ...[more]

PMID: 29938027

Similar Datasets

Enantioselective cyanation of benzylic C-H bonds via copper-catalyzed radical relay.

Project description:Direct methods for stereoselective functionalization of sp3-hybridized carbon-hydrogen [C(sp3)-H] bonds in complex organic molecules could facilitate much more efficient preparation of therapeutics and agrochemicals. Here, we report a copper-catalyzed radical relay pathway for enantioselective conversion of benzylic C-H bonds into benzylic nitriles. Hydrogen-atom abstraction affords an achiral benzylic radical that undergoes asymmetric C(sp3)-CN bond formation upon reaction with a chiral copper catalyst. The reactions proceed efficiently at room temperature with the benzylic substrate as limiting reagent, exhibit broad substrate scope with high enantioselectivity (typically 90 to 99% enantiomeric excess), and afford products that are key precursors to important bioactive molecules. Mechanistic studies provide evidence for diffusible organic radicals and highlight the difference between these reactions and C-H oxidations mediated by enzymes and other catalysts that operate via radical rebound pathways.

| S-EPMC5488708 | biostudies-literature

Copper-catalyzed ?-boration of ?,?-unsaturated carbonyl compounds with tetrahydroxydiborane.

Project description:The copper-catalyzed ?-boration of ?,?-unsaturated carbonyl compounds with tetrahydroxydiborane has been developed. This diboron reagent allows direct, efficient access to boronic acids and their derivatives. Primary, secondary, and tertiary ?,?-unsaturated amides are converted to the corresponding ?-trifluoroboratoamides in good to excellent yields. The ?-boration of a variety of ?,?-unsaturated esters and ketones is also reported.

| S-EPMC3162992 | biostudies-literature

Enantioselective synthesis of cyclobutanes via sequential Rh-catalyzed bicyclobutanation/Cu-catalyzed homoconjugate addition.

Project description:Enantiomerically enriched cyclobutanes are constructed by a three-component process in which t-butyl (E)-2-diazo-5-arylpent-4-enoates are treated with Rh2(S-NTTL)4 to provide enantiomerically enriched bicyclobutanes, which can subsequently engage in homoconjugate addition/enolate trapping sequence to give densely functionalized cyclobutanes with high diastereoselectivity. This three-component, two-catalyst procedure can be carried out in a single flask. Rh2(S-NTTL)4-catalyzed reaction of t-butyl (Z)-2-diazo-5-phenylpent-4-enoate gives the Büchner cyclization product in excellent enantioselectivity.

| S-EPMC3908885 | biostudies-literature

Directed, Palladium(II)-Catalyzed Enantioselective anti-Carboboration of Alkenyl Carbonyl Compounds.

Project description:A substrate-directed enantioselective anti-carboboration reaction of alkenes has been developed, wherein a carbon-based nucleophile and a boron moiety are installed across the C=C bond through a 5-membered palladacycle intermediate. A preliminary result also shows it is possible to extend this reaction to alkenes that are more distal from the directing group and react via a 6-membered palladacycle. The reaction is promoted by a palladium(II) catalyst and a monodentate oxazoline ligand. A range of enantioenriched secondary alkylboronate products were obtained with moderate to high enantioselectivity that could be further upgraded by recrystallization. This work represents an efficient method to synthesize versatile and valuable alkylboronate building blocks. Building on an earlier mechanistic proposal by Peng, He, and Chen, a revised model is proposed to account for the stereoconvergent nature of this transformation.

| S-EPMC6889887 | biostudies-literature

Copper-Catalyzed Synthesis of Hindered Ethers from α-Bromo Carbonyl Compounds.

Project description:A catalytic method for the synthesis of sterically hindered ethers and thioethers from α-bromo carbonyl compounds and the corresponding nucleophiles using an inexpensive Cu(I) catalytic system is reported. This facile transformation takes place at ambient temperature and does not require the exclusion of air or moisture; thus, it is well-suited for the functionalization and derivatization of complex organic molecules.

| S-EPMC7802898 | biostudies-literature

Tertiary aminourea-catalyzed enantioselective iodolactonization.

Project description: Not available

| S-EPMC2993562 | biostudies-literature

Copper-Catalyzed Synthesis of Trifluoroethylarenes from Benzylic Bromodifluoroacetates.

Project description:Trifluoroethylarenes are found in a variety of biologically active molecules, and strategies for accessing this substructure are important for developing therapeutic candidates and biological probes. Trifluoroethylarenes can be directly accessed via nucleophilic trifluoromethylation of benzylic electrophiles; however, current catalytic methods do not effectively transform electron-deficient substrates and heterocycles. To address this gap, we report a Cu-catalyzed decarboxylative trifluoromethylation of benzylic bromodifluoroacetates. To account for the tolerance of sensitive functional groups, we propose an inner-sphere mechanism of decarboxylation.

| S-EPMC4546558 | biostudies-literature

Cu-Catalyzed Diastereo- and Enantioselective Reactions of γ,γ-Disubstituted Allyldiboron Compounds with Ketones.

Project description:A catalytic diastereo- and enantioselective method for the preparation of complex tertiary homoallylic alcohols containing a vicinal quaternary carbon stereogenic center and a versatile alkenylboronic ester is disclosed. Transformations are promoted by 5 mol % of a readily available copper catalyst bearing a bulky monodentate phosphoramidite ligand, which is essential for attaining both high dr and er. Reactions proceed with a wide variety of ketones and allylic 1,1-diboronate reagents, which enables the efficient preparation of diverse array of molecular scaffolds.

| S-EPMC7230022 | biostudies-literature

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups.

Project description:Starting from ?-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine.

| S-EPMC4979759 | biostudies-other

Copper-Catalyzed Addition of Grignard Reagents to in situ Generated Indole-Derived Vinylogous Imines.

Project description:Chiral indole derivatives are ubiquitous motifs in pharmaceuticals and alkaloids. Herein, the first protocol for catalytic asymmetric conjugate addition of Grignard reagents to various sulfonyl indoles, offering a straightforward approach for the synthesis of chiral 3-sec-alkyl-substituted indoles in high yields and enantiomeric ratios is presented. This methodology makes use of a chiral catalyst based on copper phosphoramidite complexes and in situ formation of vinylogous imine intermediates.

| S-EPMC7918645 | 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