Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Catalytic asymmetric Friedel-Crafts alkylation of unprotected indoles with nitroalkenes using a novel chiral Yb(OTf)₃-pybox complex.

ABSTRACT: Chiral chloro-indeno pybox has served as a new ligand for the Yb(OTf)₃-catalyzed asymmetric Friedel-Crafts alkylation reaction of indoles with nitroalkenes. The tunable nature of pybox ligands enables the rational design of catalysts for optimal performance in terms of both activity and stereoselectivity in a Friedel-Crafts-type reaction. Good to excellent yields and enantioselectivities were obtained for a relatively wide range of substrates, including sterically hindered compounds, under optimized reaction conditions.

SUBMITTER: Karimi B

PROVIDER: S-EPMC10484919 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Catalytic asymmetric Friedel-Crafts alkylation of unprotected indoles with nitroalkenes using a novel chiral Yb(OTf)3-pybox complex.

Karimi Babak B Jafari Ehsan E Mansouri Fariborz F Tavakolian Mina M

Scientific reports 20230907 1

Chiral chloro-indeno pybox has served as a new ligand for the Yb(OTf)3-catalyzed asymmetric Friedel-Crafts alkylation reaction of indoles with nitroalkenes. The tunable nature of pybox ligands enables the rational design of catalysts for optimal performance in terms of both activity and stereoselectivity in a Friedel-Crafts-type reaction. Good to excellent yields and enantioselectivities were obtained for a relatively wide range of substrates, including sterically hindered compounds, ...[more]

PMID: 37679477

Similar Datasets

Ni(ii)/spiroBox-catalyzed asymmetric Friedel-Crafts alkylation of indoles with nitroalkenes.

Project description:Nickel complexes of chiral spiroBox ligand catalyzed Friedel-Crafts alkylation reaction of indoles with nitroalkenes. Excellent yields (up to 99%) and enantiomeric excess (ee) values (up to 97%) were obtained with a broad scope of substrates. This catalytic system provides a facile synthesis of optically active 2-indolyl-1-nitro derivatives with high yield and enantioselectivity.

| S-EPMC11891994 | biostudies-literature

Friedel-Crafts Alkylation of Indoles with Trichloroacetimidates.

Project description:Substituted indole scaffolds are often utilized in medicinal chemistry as they regularly possess significant pharmacological activity. Therefore the development of simple, inexpensive and efficient methods for alkylating the indole heterocycle continues to be an active research area. Reported are reactions of trichloroacetimidate electrophiles and indoles to address the challenges of accessing alkyl decorated indole structures. These alkylations perform best when either the indole or the imidate is functionalized with electron withdrawing groups to avoid polyalkylation.

| S-EPMC6720118 | biostudies-literature

Rose bengal as photocatalyst: visible light-mediated Friedel-Crafts alkylation of indoles with nitroalkenes in water.

Project description:A novel and facile visible-light-mediated alkylation of indoles and nitroalkenes has been developed. In this protocol, rose bengal acts as a photosensitizer, and environmentally benign water was used as the green and efficient reaction medium. Indoles reacted smoothly with nitroalkenes under the irradiation of visible-light and generated corresponding 3-(2-nitroalkyl)indoles in moderate to good yields (up to 87%).

| S-EPMC9049176 | biostudies-literature

Synthesis of 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols through regioselective Friedel-Crafts alkylation of indoles with β-(trifluoroacetyl)coumarins catalyzed by Sc(OTf)3.

Project description:A highly efficient Friedel-Crafts alkylation of indole derivatives with β-(trifluoroacetyl)coumarins using Sc(OTf)3 as a catalyst has been developed, which gives regioselective 1,2-adducts to afford 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols. A series of tertiary trifluoroethanols containing different indole and coumarin groups were synthesized in moderate to excellent yields (up to 95%) in the presence of 5 mol% catalyst in a short time (only 2 minutes at least). A mechanism of the reaction, in which the trace amount of water plays the role of proton transfer in catalyzing circulation was proposed and confirmed.

| S-EPMC9051918 | biostudies-literature

A cycloisomerization/Friedel-Crafts alkylation strategy for the synthesis of pyrano[3,4-b]indoles.

Project description:The synthesis of pyrano[3,4-b]indoles is described. The reaction sequence involves Sonogashira coupling of dihydropyran propargyl ether scaffolds with iodoanilines to afford intermediate indoles. Lewis acid-catalyzed ionization of the dihydropyrans, followed by intramolecular C3 alkylation of the indole, provides the title compounds.

| S-EPMC3146574 | biostudies-literature

C3-Alkylation of Imidazo[1,2-a]pyridines via Three-Component Aza-Friedel-Crafts Reaction Catalyzed by Y(OTf)3.

Project description:As an important class of nitrogen-containing fused heterocyclic compounds, imidazo[1,2-a]pyridines often exhibit significant biological activities, such as analgesic, anticancer, antiosteoporosis, anxiolytic, etc. Using Y(OTf)3 as a Lewis acid catalyst, a simple and efficient method has been developed for the synthesis of C3-alkylated imidazo[1,2-a]pyridines through the three-component aza-Friedel-Crafts reaction of imidazo[1,2-a]pyridines, aldehydes, and amines in the normal air atmosphere without the protection of inert gas and special requirements for anhydrous and anaerobic conditions. A series of imidazo[1,2-a]pyridine derivatives were obtained with moderate to good yields, and their structures were confirmed by 1H NMR, 13C NMR, and HRMS. Furthermore, this conversion has the advantages of simple operation, excellent functional group tolerance, high atomic economy, broad substrate scope, and can achieve gram-level reactions. Notably, this methodology may be conveniently applied to the further design and rapid synthesis of potential biologically active imidazo[1,2-a]pyridines with multifunctional groups.

| S-EPMC11313794 | biostudies-literature

Toward the total synthesis of elisapterosin B: A Hg(OTf)(2)-promoted diastereoselective intramolecular Friedel-Crafts alkylation reaction.

Project description:As part of an approach to the synthesis of the antitubercular agent elisapterosin B, we prepared two different chiral, non-racemic olefinic substrates and examined their diastereoselective ring closure using mercury salts. The effort yielded potential precurors to elisapterosin B in good yield with good to excellent diastereocontrol.

| S-EPMC3050487 | biostudies-literature

AlCl₃·6H₂O-Catalyzed Friedel-Crafts Alkylation of Indoles by the para-Quinone Methide Moiety of Celastrol.

Project description:A classical Friedel-Crafts alkylation of different indoles catalyzed by AlCl₃·6H₂O has been developed for a well-known important natural product, celastrol, resulting in a series of derivatives for further biological evaluation. The catalyst loading was reduced to 5 mol %, the reaction proceeds at ambient temperature and reaction time is only 3 h. The product yields range from 20% to 99%. A reaction mechanism is also proposed, based on our experiment results.

| S-EPMC6154665 | biostudies-literature

Electrifying Friedel-Crafts Intramolecular Alkylation toward 1,1-Disubstituted Tetrahydronaphthalenes.

Project description:In this work, we successfully employed electrochemical conditions to promote a Hofer-Moest, intramolecular Friedel-Crafts alkylation sequence. The reaction proceeds under mild conditions, employing carboxylic acids as starting materials. Notably, the electrochemical process performed in batch was adapted to a continuous flow electrolysis apparatus to provide a significant improvement. This catalyst-free, electrochemical approach produces an array of tetrahydronaphthalenes that could be used for API synthesis.

| S-EPMC10729024 | biostudies-literature

Tandem Friedel-Crafts-Alkylation-Enantioselective-Protonation by Artificial Enzyme Iminium Catalysis.

Project description:The incorporation of organocatalysts into protein scaffolds holds the promise of overcoming some of the limitations of this powerful catalytic approach. Previously, we showed that incorporation of the non-canonical amino acid para-aminophenylalanine into the non-enzymatic protein scaffold LmrR forms a proficient and enantioselective artificial enzyme (LmrR_pAF) for the Friedel-Crafts alkylation of indoles with enals. The unnatural aniline side-chain is directly involved in catalysis, operating via a well-known organocatalytic iminium-based mechanism. In this study, we show that LmrR_pAF can enantioselectively form tertiary carbon centres not only during C-C bond formation, but also by enantioselective protonation, delivering a proton to one face of a prochiral enamine intermediate. The importance of various side-chains in the pocket of LmrR is distinct from the Friedel-Crafts reaction without enantioselective protonation, and two particularly important residues were probed by exhaustive mutagenesis.

| S-EPMC9313897 | biostudies-literature