Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Bronsted Acid-Catalyzed Formal [2 + 2 + 1] Annulation for the Modular Synthesis of Tetrahydroindoles and Tetrahydrocyclopenta[ b]pyrroles.

ABSTRACT: An expedient synthesis of tetrahydroindoles and tetrahydrocyclopenta[ b]pyrroles, highlighted by Brønsted acid catalyzed formal [2 + 2 + 1] annulation reaction, is reported. Using three readily accessible reaction components, i.e., an electrophilic species in silyloxyallyl cations and two distinct nucleophiles in silylenol ethers and amines, our chemistry enables the assembly and functionalization of these biologically important N-heterocycles in a highly modular manner.

SUBMITTER: Malone JA

PROVIDER: S-EPMC7055494 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Brønsted Acid-Catalyzed Formal [2 + 2 + 1] Annulation for the Modular Synthesis of Tetrahydroindoles and Tetrahydrocyclopenta[ b]pyrroles.

Malone Joshua A JA Toussel Courtney E CE Fronczek Frank R FR Kartika Rendy R

Organic letters 20190429 10

An expedient synthesis of tetrahydroindoles and tetrahydrocyclopenta[ b]pyrroles, highlighted by Brønsted acid catalyzed formal [2 + 2 + 1] annulation reaction, is reported. Using three readily accessible reaction components, i.e., an electrophilic species in silyloxyallyl cations and two distinct nucleophiles in silylenol ethers and amines, our chemistry enables the assembly and functionalization of these biologically important N-heterocycles in a highly modular manner. ...[more]

PMID: 31033299

Similar Datasets

Highly stereoselective Bronsted acid catalyzed synthesis of spirooxindole pyrans.

Project description:A Brønsted acid-catalyzed Prins-type cyclization sequence to construct spirooxindole pyrans in high yields and excellent diastereoselectivity has been developed. The combination of a β-hydroxy dioxinone fragment and isatin dimethyl acetal generate oxa-spirooxindoles efficiently. These compounds are diversifiable scaffolds that tap into the rich chemistry of dioxinones.

| S-EPMC3115630 | biostudies-literature

Gold(I)-Catalyzed Synthesis of 3-Sulfenyl Pyrroles and Indoles by a Regioselective Annulation of Alkynyl Thioethers.

Project description:The combination of nucleophilic nitrenoids and π-acid catalysis has emerged as a powerful tool in heterocycle synthesis. Accessing more varied heterocycle-substitution patterns by maintaining the same reaction pathways across different alkynes remains a challenge. Here we show that Au(I) catalysis of isoxazole-based nitrenoids with alkynyl thioethers provides controlled access to (3 + 2) annulation by a regioselective addition β to the sulfenyl group. The reaction with isoxazole-containing nitrenoids delivers sulfenylated pyrroles and indoles as single regioisomers bearing useful functional groups and structural variety.

| S-EPMC8291588 | biostudies-literature

Copper-catalyzed condensation of imines and α-diazo-β-dicarbonyl compounds: modular and regiocontrolled synthesis of multisubstituted pyrroles.

Project description:In the presence of a copper(ii) catalyst, enolizable imines bearing various N-substituents and α-diazo-β-ketoesters undergo denitrogenative and dehydrative condensation to afford highly substituted pyrroles in moderate to good yields with exclusive regioselectivity. The reaction likely involves nucleophilic addition of the imine nitrogen to a copper carbenoid, tautomerization of the resulting azomethine ylide to an α-enaminoketone, and a subsequent enamine-ketone cyclocondensation. With Yb(OTf)3 as a unique cocatalyst, α-diazo-β-diketones also participate in the same condensation reaction. The present reaction is applicable to acyclic, exocyclic, and endocyclic imines with tolerance of a broad range of functional groups and heterocyclic moieties, thus opening a new convenient route for the synthesis of the lamellarin family of natural products.

| S-EPMC6054072 | biostudies-literature

Chiral Bronsted Acid-Catalyzed Asymmetric Synthesis of N-Aryl-cis-aziridine Carboxylate Esters.

Project description:We report a multi-component asymmetric Brønsted acid-catalyzed aza-Darzens reaction which is not limited to specific aromatic or heterocyclic aldehydes. Incorporating alkyl diazoacetates and, important for high ee's, ortho-tert-butoxyaniline our optimized reaction (i.e. solvent, temperature and catalyst study) affords excellent yields (61-98 %) and mostly >90 % optically active cis-aziridines. (+)-Chloramphenicol was generated in 4 steps from commercial starting materials. A tentative mechanism is outlined.

| S-EPMC5502890 | biostudies-literature

Copper-catalyzed intermolecular formal (5 + 1) annulation of 1,5-diynes with 1,2,5-oxadiazoles.

Project description:One-carbon homologation reactions based on one-carbon insertion into the N-O bond of heterocycles have received tremendous interest over the past decades. However, these protocols have to rely on the use of hazardous and not easily accessible diazo compounds as precursors, and examples of the relevant asymmetric catalysis have not been reported. Here we show that a copper-catalyzed intermolecular formal (5 + 1) annulation of 1,5-diynes with 1,2,5-oxadiazoles involving one-carbon insertion into the heterocyclic N-O bond via non-diazo approach. This method enables practical and atom-economic synthesis of valuable pyrrole-substituted oxadiazines in generally moderate to good yields under mild reaction conditions. In addition, the possibility of such an asymmetric formal (5 + 1) annulation also emerges.

| S-EPMC10497616 | biostudies-literature

Chiral Bronsted acid-catalyzed allylboration of aldehydes.

Project description:The catalytic enantioselective allylation of aldehydes is a long-standing problem of considerable interest to the chemical community. We disclose a new high-yielding and highly enantioselective chiral Brønsted acid-catalyzed allylboration of aldehydes. The reaction is shown to be highly general, with a broad substrate scope that covers aryl, heteroaryl, alpha,beta-unsaturated, and aliphatic aldehydes. The reaction conditions are also shown to be effective for the catalytic enantioselective crotylation of aldehydes. We believe that the high reactivity of the allylboronate is due to protonation of the boronate oxygen by the chiral phosphoric acid catalyst.

| S-EPMC2928988 | biostudies-literature

Bronsted acid-catalyzed aromatic annulation of alkoxyallenes with naphthols: a reaction sequence to larger ?-conjugated naphthopyrans with aggregation-induced emission characters.

Project description:A practical and readily scalable reaction sequence was developed for the straightforward synthesis of a new family of larger ?-conjugated naphthopyrans by a Brønsted acid-catalyzed aromatic annulation of alkoxyallenes with inert naphthols. The cascade pathway involves allylation/cyclization/debenzyloxylation/isomerization/dehydration. The new class of solid state diphenylmethylene substituted naphthopyrans are fluorescent emissive and proved to have aggregation-induced emission (AIE) behavior.

| S-EPMC6346396 | biostudies-literature

Bronsted acid-catalyzed one-pot synthesis of indoles from o-aminobenzyl alcohols and furans.

Project description:Brönsted acid-catalyzed one-pot synthesis of indoles from o-aminobenzyl alcohols and furans has been developed. This method operates via the in situ formation of aminobenzylfuran, followed by its recyclization into the indole core. The method proved to be efficient for substrates possessing different functional groups, including -OMe, -CO2Cy, and -Br. The resulting indoles can easily be transformed into diverse scaffolds, including 2,3- and 1,2-fused indoles, and indoles possessing an α,β-unsaturated ketone moiety at the C-2 position.

| S-EPMC3923594 | biostudies-literature

Amino acid salt catalyzed intramolecular Robinson annulation.

Project description:The silica gel absorbed amino acid salt catalyzed asymmetric intramolecular Robinson annulation reaction has been developed; up to 97% ee was obtained with this readily recoverable organocatalyst.

| S-EPMC2771404 | biostudies-literature

Palladium-catalyzed synthesis of N-vinyl pyrroles and indoles.

Project description:A stereospecific palladium-catalyzed N-vinylation of azaheterocycles with vinyl triflates is described. Cyclic and acyclic vinyl triflates along with nonnucleophilic azaheterocycles were found to be substrates for this palladium-catalyzed synthesis of N-vinyl pyrrole and indole derivatives.

| S-EPMC5548004 | 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