Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Preparative Synthesis of Highly Substituted Tetrahydropyridines via a Rh(I)-Catalyzed C-H Functionalization Sequence.

ABSTRACT: We report a Rh(I)-catalyzed C-H activation/alkenylation/electrocyclization cascade and subsequent reduction for the synthesis of highly substituted tetrahydropyridines. These products can be accessed on a gram scale with low catalyst loadings and at high reaction concentrations. Additionally, a modified Rh-catalyst, prepared from [RhCl(cod)]₂ as a robust bench-stable precatalyst was developed to enable straightforward reaction set up without the use of a glovebox. To demonstrate the practicality of this reaction, a >100 mmol scale Rh-catalyzed cascade reaction sequence utilizing the air-stable precatalyst [RhCl(cod)]₂ was performed on the bench to furnish the pure tetrahydropyridine product in 93% yield.

SUBMITTER: Mesganaw T

PROVIDER: S-EPMC4183668 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Preparative Synthesis of Highly Substituted Tetrahydropyridines via a Rh(I)-Catalyzed C-H Functionalization Sequence.

Mesganaw Tehetena T Ellman Jonathan A JA

Organic process research & development 20140829 9

We report a Rh(I)-catalyzed C-H activation/alkenylation/electrocyclization cascade and subsequent reduction for the synthesis of highly substituted tetrahydropyridines. These products can be accessed on a gram scale with low catalyst loadings and at high reaction concentrations. Additionally, a modified Rh-catalyst, prepared from [RhCl(cod)]<sub>2</sub> as a robust bench-stable precatalyst was developed to enable straightforward reaction set up without the use of a glovebox. To demonstrate the p ...[more]

PMID: 25288872

Similar Datasets

Convergent Synthesis of Diverse Tetrahydropyridines via Rh(I)-Catalyzed C-H Functionalization Sequences.

Project description:A Rh-catalyzed C-H bond activation/alkenylation/electrocyclization cascade reaction provides diverse 1,2-dihydropyridines from simple and readily available precursors. The reaction can be carried out at low (<1%) Rh-catalyst loadings, and the use of the robust, air-stable Rh precatalyst, [RhCl(cod)]2, enables the cascade reaction to be easily performed on the benchtop. The 1,2-dihydropyridine products serve as extremely versatile synthetic intermediates for further elaboration often without isolation. The addition of electrophiles under kinetic or thermodynamic conditions provides a wide range of iminiums. Subsequent addition of a nucleophile then generates a diverse array of differently substituted piperidine products. Additionally, [3 + 2] and [4 + 2] cycloadditions of the 1,2-dihydropyridine intermediate provides access to bridged bicyclic structures such as tropanes and isoquinuclidines. These concise reaction sequences enable the formation of highly substituted piperidines in synthetically useful yields with excellent diastereoselectivity.

| S-EPMC4183667 | biostudies-other

Asymmetric synthesis of ?-branched amines via Rh(III)-catalyzed C-H bond functionalization.

Project description:The first asymmetric intermolecular addition of non-acidic C-H bonds to imines is reported. The use of the activating N-perfluorobutanesulfinyl imine substituent is essential for achieving sufficient reactivity and provides outstanding diastereoselectivity (>98:2 dr). Straightforward removal of the sulfinyl group with HCl yields the highly enantiomerically enriched amine hydrochlorides.

| S-EPMC4105057 | biostudies-literature

Regio- and Diastereoselective Synthesis of Highly Substituted, Oxygenated Piperidines from Tetrahydropyridines.

Project description:Diastereoselective epoxidation and regioselective ring-opening methods were developed for the synthesis of densely substituted, oxygenated piperidines from two classes of tetrahydropyridines with distinct stereochemical displays of functionalities. A new and practical in situ prepared epoxidation reagent was developed for the diastereoselective epoxidation of one class of sterically hindered tetrahydropyridines. The novel bifunctional epoxidation reagent, 2-carboperoxy-3,4,5,6-tetrafluorobenzoic acid, was designed to incorporate highly reactive percarboxy acid and pendant carboxylic acid groups, which through hydrogen bonding to the amino group successfully overrode steric effects and directed epoxidation to occur at the more hindered face of the tetrahydropyridine. Nucleophilic ring-opening of the epoxides with water, alcohols, and HF proceeded with high regioselectivity, affording piperidinol products with adjacent tetrasubstituted carbons.

| S-EPMC4496584 | biostudies-literature

Modular Synthesis of Highly Substituted 3-Azapyrroles by Rh(II)-Catalyzed N-H Bond Insertion and Cyclodehydration.

Project description:A modular synthesis of highly substituted 3-azapyrroles has been developed using a three-step sequence comprising copper-catalyzed alkyne-azide cycloaddition (CuAAC), N-H bond insertion, and cyclodehydration. 1-Sulfonyl-1,2,3-triazoles (1-STs) can be accessed from common alkyne and sulfonyl azide building blocks by CuAAC using CuTC. Rhodium(II)-acetate-promoted 1-ST denitrogenation results in highly electrophilic rhodium azavinyl carbenes that, here, underwent insertion into the N-H bond of secondary α-aminoketones to form 1,2-aminoalkenes. These products were cyclized and dehydrated using BF3·OEt2 into highly substituted 3-azapyrroles. The three steps (CuAAC, N-H bond insertion, and cyclodehydration) could be telescoped into a one-pot process. The method proved to be highly efficient and tolerated a wide range of substituents.

| S-EPMC9764362 | biostudies-literature

Highly substituted 2-amido-furans from Rh(II)-catalyzed cyclopropenations of ynamides.

Project description:Rh(II)-catalyzed cyclopropenations of ynamides are described. Although an actual amido-cyclopropene intermediate may not be involved, these reactions provide a facile entry to highly substituted 2-amido-furans, thereby formerly constituting a [3 + 2] cycloaddition. An application of these de novo 2-amido-furans in N-tethered intramolecular [4 + 2] cycloadditions is also illustrated, leading to dihydroindoles and tetrahydroquinolines.

| S-EPMC2813717 | biostudies-literature

Rh-Catalyzed Highly Enantioselective Synthesis of Aliphatic Sulfonyl Fluorides.

Project description:Rh-catalyzed, highly enantioselective (up to 99.8% ee) synthesis of aliphatic sulfonyl fluorides was accomplished. This protocol provides a portal to a class of novel 2-aryl substituted chiral sulfonyl fluorides, which are otherwise extremely difficult to access. This asymmetric synthesis has the feature of mild conditions, excellent functional group compatibility, and wide substrate scope (51 examples) generating a wide array of structurally unique chiral ?-arylated sulfonyl fluorides for sulfur(VI) fluoride exchange (SuFEx) click reaction and drug discovery.

| S-EPMC6889689 | biostudies-literature

A concise synthesis of highly substituted imidazoles via copper-mediated oxidative C-H functionalization.

Project description:We herein report a simple and concise route for the synthesis of highly substituted imidazole derivatives via copper-mediated oxidative C-H functionalization in good to high yields. The advantage of the reaction lies in its mild reaction conditions and readily available starting materials.

| S-EPMC4034134 | biostudies-literature

Highly Regioselective Synthesis of Substituted Isoindolinones <i>via</i> Ruthenium-Catalyzed Alkyne Cyclotrimerizations.

Project description:(Cyclooctadiene)(pentamethylcyclopentadiene)ruthenium chloride [Cp*RuCl(cod)] has been used to catalyze the regioselective cyclization of amide-tethered diynes with monosubstituted alkynes to give polysubstituted isoindolinones. Notably, the presence of a trimethylsilyl group on the diyne generally led to complete control over the regioselectivity of the alkyne cyclotrimerization. The cyclization reaction worked well in a sustainable non-chlorinated solvent and was tolerant of moisture. The optimized conditions were effective with a diverse range of alkynes and diynes. The 7-silylisoindolinone products could be halogenated, protodesilylated or ring opened to access a range of usefully functionalized products.

| S-EPMC3793232 | biostudies-literature

Phosphine-catalyzed [5+1] annulation of ?-sulfonamido-substituted enones with N-sulfonylimines: a facile synthesis of tetrahydropyridines.

Project description:Phosphine-catalyzed [5+1] annulation of ?-sulfonamido-substituted enones with N-sulfonylimines for the synthesis of 1,2,3,6-tetrahydropyridines is developed. The reaction proceeds smoothly under mild reaction conditions to give the annulation products in moderate to excellent yields. Mechanistic exploration of this new annulation shows that the ?-sulfonamido-substituted enone and the N-sulfonylimine serve as C5 and C1 synthons to furnish the annulation, respectively. Using chiral phosphine as the catalyst, an asymmetric variant of the model reaction gave the chiral product in up to 73% ee.

| S-EPMC5892350 | biostudies-literature

Diaryldiazoketones as Effective Carbene Sources for Highly Selective Rh(II)-Catalyzed Intermolecular C-H Functionalization.

Project description:A novel donor/acceptor carbene intermediate has been developed using diaryldiazoketones as carbene precursors. In the presence of the chiral dirhodium catalyst, Rh2(S-TPPTTL)4, diaryldiazoketones undergo highly regio-, stereo-, and diastereoselective C-H functionalization of activated and unactivated secondary and tertiary C-H bonds. Computational studies revealed that the arylketo group behaves differently than the carboxylate acceptor group because the orientation of the arylketo group predetermines which face of the carbene will be attacked.

| S-EPMC10979447 | 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