Browse
Submit Data
Databases
API
Help

Dataset Information

12 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A cheap metal for a challenging task: nickel-catalyzed highly diastereo- and enantioselective hydrogenation of tetrasubstituted fluorinated enamides.

ABSTRACT: Nickel-catalyzed asymmetric hydrogenation of challenging tetrasubstituted fluorinated enamides has been achieved, affording chiral ?-fluoro-?-amino esters in high yields with excellent diastereo- and enantioselectivities (up to 98% yield, >99?:?1 dr, up to >99% ee). Deuterium-labeling experiments and control experiments were conducted to probe the mechanism, and the results indicated that the acidity of the solvent plays a critical role in the control of diastereoselectivity by trapping the adduct of nickel hydride to C[double bond, length as m-dash]C bonds via protonolysis, giving the hydrogenation product with stereospecific syn-selectivity. This protocol provides efficient access to chiral ?-fluoro-?-amino esters which have important potential applications in organic synthesis and medicinal chemistry.

SUBMITTER: Guan YQ

PROVIDER: S-EPMC6335620 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

A cheap metal for a challenging task: nickel-catalyzed highly diastereo- and enantioselective hydrogenation of tetrasubstituted fluorinated enamides.

Guan Yu-Qing YQ Han Zhengyu Z Li Xiuxiu X You Cai C Tan Xuefeng X Lv Hui H Zhang Xumu X

Chemical science 20181016 1

Nickel-catalyzed asymmetric hydrogenation of challenging tetrasubstituted fluorinated enamides has been achieved, affording chiral α-fluoro-β-amino esters in high yields with excellent diastereo- and enantioselectivities (up to 98% yield, >99 : 1 dr, up to >99% ee). Deuterium-labeling experiments and control experiments were conducted to probe the mechanism, and the results indicated that the acidity of the solvent plays a critical role in the control of diastereoselectivity by trapping the addu ...[more]

PMID: 30746080

Similar Datasets

Highly Enantioselective Iridium-Catalyzed Hydrogenation of Cyclic Enamides.

Project description:The MaxPHOX-Ir catalyst system provided the highest selectivity ever reported for the reduction of cyclic enamides derived from ?- and ?-tetralones. This result indicates that iridium catalysts are also proficient in reducing alkenes bearing metal-coordinating groups. In the present system, selectivity was pressure-dependent: In most cases, a decrease in the H2 pressure to 3?bar resulted in an increase in enantioselectivity. Moreover, the process can be carried out in environmentally friendly solvents, such as methanol and ethyl acetate, with no loss of selectivity.

| S-EPMC5084810 | biostudies-other

Highly enantioselective hydrogenation of enamides catalyzed by chiral phosphoric acids.

Project description:A highly enantioselective hydrogenation of enamides catalyzed by a dual chiral-achiral acid system was developed. By employing a substoichiometric amount of a chiral phosphoric acid and acetic acid, catalyst loadings as low as 1 mol % of the chiral catalyst were sufficient to provide excellent yield and enantioselectivity of the reduction product.

| S-EPMC2765520 | biostudies-literature

Diastereo- and Enantioselective Iridium Catalyzed Carbonyl (?-Cyclopropyl)allylation via Transfer Hydrogenation.

Project description:The first examples of diastereo- and enantioselective carbonyl ?-(cyclopropyl)allylation are reported. Under the conditions of iridium catalyzed transfer hydrogenation using the chiral precatalyst (R)-Ir-I modified by SEGPHOS, carbonyl ?-(cyclopropyl)allylation may be achieved with equal facility from alcohol or aldehyde oxidation levels. This methodology provides a conduit to hitherto inaccessible inaccessible enantiomerically enriched cyclopropane-containing architectures.

| S-EPMC4627847 | biostudies-literature

Barbier-type anti-Diastereo- and Enantioselective Synthesis of ?-Trimethylsilyl, Fluorinated Methyl, Phenylthio Homoallylic Alcohols.

Project description:Catalytic Asymmetric allylation of aldehydes with functionalized allylic reagents represents an important process in synthetic organic chemistry because the resulting chiral homoallylic alcohols are valuable building blocks in diverse research fields. Despite the obvious advantages of allyl halides as allylation reagent under Barbier-type conditions, catalytic asymmetric version using functionalized allyl halides remains largely underdeveloped. Here, we addressed this issue by employing a chromium-catalysis system. The use of readily available allyl bromides with ? substitutions including trimethylsilyl, fluorinated methyl and phenylthio groups provided an efficient and convenient method to introduce those privileged functionalities into homoallylic alcohols. Good yields, high anti-diastereo- and excellent enantioselectivities were achieved under mild reaction conditions.

| S-EPMC5501818 | biostudies-other

Diastereo- and enantioselective anti-alkoxyallylation employing allylic gem-dicarboxylates as allyl donors via iridium-catalyzed transfer hydrogenation.

Project description:Enantioselective transfer hydrogenation of gem-dibenzoate 1e in the presence of aromatic, alpha,beta-unsaturated, or aliphatic aldehydes 2a-i mediated by isopropyl alcohol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid, and (R)-SEGPHOS delivers products of alkoxyallylation 3a-i, 4a, 4e, 4f, and 4i in good isolated yields (62-82%) with good to excellent diastereoselectivities (7:1 to 18:1 dr) and exceptional enantioselectivities (90-99% ee). This protocol provides an alternative to the use of premetalated nucleophiles in carbonyl alkoxyallylation.

| S-EPMC2824430 | biostudies-literature

Asymmetric Hydrogenation of Unfunctionalized Tetrasubstituted Acyclic Olefins.

Project description:Asymmetric hydrogenation has evolved as one of the most powerful tools to construct stereocenters. However, the asymmetric hydrogenation of unfunctionalized tetrasubstituted acyclic olefins remains the pinnacle of asymmetric synthesis and an unsolved challenge. We report herein the discovery of an iridium catalyst for the first, generally applicable, highly enantio- and diastereoselective hydrogenation of such olefins and the mechanistic insights of the reaction. The power of this chemistry is demonstrated by the successful hydrogenation of a wide variety of electronically and sterically diverse olefins in excellent yield and high enantio- and diastereoselectivity.

| S-EPMC7141762 | biostudies-literature

Isomerization of N-Allyl Amides To Form Geometrically Defined Di-, Tri-, and Tetrasubstituted Enamides.

Project description:Enamides represent bioactive pharmacophores in various natural products, and have become increasingly common reagents for asymmetric incorporation of nitrogen functionality. Yet the synthesis of the requisite geometrically defined enamides remains problematic, especially for highly substituted and Z-enamides. Herein we wish to report a general atom economic method for the isomerization of a broad range of N-allyl amides to form Z-di-, tri-, and tetrasubstituted enamides with exceptional geometric selectivity. This report represents the first examples of a catalytic isomerization of N-allyl amides to form nonpropenyl disubstituted, tri- and tetrasubstituted enamides with excellent geometric control. Applications of these geometrically defined enamides toward the synthesis of cis vicinal amino alcohols and tetrasubstituted α-borylamido complexes are discussed.

| S-EPMC5726938 | biostudies-literature

Catalytic Diastereo- and Enantioselective Fluoroamination of Alkenes.

Project description:The stereoselective synthesis of syn-?-fluoroaziridine building blocks via chiral aryl iodide-catalyzed fluorination of allylic amines is reported. The method employs HF-pyridine as a nucleophilic fluoride source together with mCPBA as a stoichiometric oxidant, and affords access to arylethylamine derivatives featuring fluorine-containing stereocenters in high diastereo- and enantioselectivity. Catalyst-controlled diastereoselectivity in the fluorination of chiral allylic amines enabled the preparation of highly enantioenriched 1,3-difluoro-2-amines bearing three contiguous stereocenters. The enantioselective catalytic method was applied successfully to other classes of multifunctional alkene substrates to afford anti-?-fluoropyrrolidines, as well as a variety of 1,2-oxyfluorinated products.

| S-EPMC5902804 | biostudies-literature

Diastereo- and enantioselective preparation of cyclopropanol derivatives.

Project description:The diastereoselective carbocupration reaction of alkoxy-functionalized cyclopropene derivatives, followed by a subsequent trapping of the resulting cyclopropylmetal species with an electrophilic source of oxygen (oxenoid) afforded various tetrasubstituted cyclopropanol derivatives in high diastereo- and enantiomeric ratios. Similarly, the enantioselective copper-catalyzed carbomagnesiation/oxidation (or amination) sequence on achiral nonfunctionalized cyclopropenes provided the desired cyclopropanol (and cyclopropylamine) derivatives in excellent diastereo- and enantiomeric excesses.

| S-EPMC6444454 | biostudies-literature

Accessing (Multi)Fluorinated Piperidines Using Heterogeneous Hydrogenation.

Project description:Fluorinated piperidines are desirable motifs for pharmaceutical and agrochemical research. Nevertheless, general synthetic access remains out of reach. Herein, we describe a simple and robust cis-selective hydrogenation of abundant and cheap fluoropyridines to yield a broad scope of (multi)fluorinated piperidines. This protocol enables the chemoselective reduction of fluoropyridines while tolerating other (hetero)aromatic systems using a commercially available heterogenous catalyst. Fluorinated derivatives of important drug compounds are prepared, and a straightforward strategy for the synthesis of enantioenriched fluorinated piperidines is disclosed.

| S-EPMC8040022 | 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