Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric Conjugate Addition of ?,?-Disubstituted Aldehydes to Nitroalkenes Organocatalyzed by Chiral Monosalicylamides from trans-Cyclohexane-1,2-Diamines.

ABSTRACT: Primary amine-salicylamides derived from chiral trans-cyclohexane-1,2-diamines are used as organocatalysts for the enantioselective conjugate addition of ?,?-disubstituted aldehydes to arylated and heteroarylated nitroalkenes. The reaction is performed in the presence of 4-dimethylaminopyridine as an additive in dichloromethane as a solvent at room temperature. The corresponding enantioenriched ?-nitroaldehydes are obtained with enantioselectivities up to 95%. Theoretical calculations are used to justify the reasons of the stereoinduction.

SUBMITTER: Martinez-Guillen JR

PROVIDER: S-EPMC6017890 | biostudies-other | 2018 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Asymmetric Conjugate Addition of α,α-Disubstituted Aldehydes to Nitroalkenes Organocatalyzed by Chiral Monosalicylamides from trans-Cyclohexane-1,2-Diamines.

Martínez-Guillén José R JR Flores-Ferrándiz Jesús J Gómez Cecilia C Gómez-Bengoa Enrique E Chinchilla Rafael R Chinchilla Rafael R

Molecules (Basel, Switzerland) 20180111 1

Primary amine-salicylamides derived from chiral <i>trans</i>-cyclohexane-1,2-diamines are used as organocatalysts for the enantioselective conjugate addition of α,α-disubstituted aldehydes to arylated and heteroarylated nitroalkenes. The reaction is performed in the presence of 4-dimethylaminopyridine as an additive in dichloromethane as a solvent at room temperature. The corresponding enantioenriched γ-nitroaldehydes are obtained with enantioselectivities up to 95%. Theoretical calculations are ...[more]

PMID: 29324713

Similar Datasets

Efficient Synthesis of Chiral Trisubstituted 1,2-Allenyl Ketones by Catalytic Asymmetric Conjugate Addition of Malonic Esters to Enynes.

Project description:An N,N'-dioxide/scandium(III) complex catalyzed, highly efficient conjugate addition of malonic esters to enynes is described. A range of trisubstituted 1,2-allenyl ketones were obtained in high yields (up to 99?%) with good d.r. (up to 95/5) and excellent ee values (97?%-99?%). Moreover, the products could be easily transformed into chiral furan and 5-hydroxypyrazoline derivatives, both of which are important skeletons of many biologically active compounds and pharmacologicals.

| S-EPMC4738401 | biostudies-literature

Organocatalytic Asymmetric Conjugate Addition of Aldehydes to Maleimides and Nitroalkenes in Deep Eutectic Solvents.

Project description:A chiral primary amine-salicylamide is used as an organocatalyst for the enantioselective conjugate addition of ?,?-disubstituted aldehydes to maleimides and nitroalkenes. The reactions are performed in deep eutectic solvents as reaction media at room temperature, leading to the corresponding adducts with enantioselectivities up to 88% (for maleimides) and 80% (for nitroalkenes). Catalyst and solvent can be recovered and reused.

| S-EPMC6891809 | biostudies-literature

Post-pulse addition of trans-cyclohexane-1,2-diol improves electrotransfer mediated gene expression in mammalian cells.

Project description:Electric field mediated gene transfer is facing a problem in expression yield due to the poor transfer across the nuclear envelope. Trans-cyclohexane-1,2-diol (TCHD) was shown to significantly increase chemically mediated transfection by collapsing the permeability barrier of the nuclear pore complex. We indeed observed a significant increase in expression by electrotransfer when cells are treated post pulse by a low non toxic concentration of TCHD. This was obtained for different pulsing conditions, cell strains and plasmid constructs. An interesting improvement in cell viability can be obtained. This can significantly enhance the non-viral gene electrical delivery.

| S-EPMC5613639 | biostudies-literature

Development of the enantioselective addition of ethyl diazoacetate to aldehydes: asymmetric synthesis of 1,2-diols.

Project description:A novel synthetic strategy toward the asymmetric synthesis of vicinal diols bearing a tertiary center is presented. The method encompasses the dinuclear Mg-catalyzed asymmetric addition of ethyl diazoacetate into several aldehydes, oxidation of the diazo functionality, and diastereoselective alkyl transfer of various organometallics into the resulting chiral ?-hydroxy-?-ketoesters to afford a diverse range of 1,2-diols in high yield, diastereoselectivity, and chirality transfer.

| S-EPMC3271135 | biostudies-literature

Reagent controlled addition of chiral sulfur ylides to chiral aldehydes.

Project description:The degree of reagent and substrate control in the reaction of chiral sulfur ylides with chiral aldehydes has been investigated. Specifically, the reactions of the two enantiomers of the chiral benzyl sulfonium salt 1 with glyceraldehyde acetonide were studied in detail. Of the two new stereogenic centers created, it was found that the C1 stereochemistry was largely controlled by the reagent, whereas control at the C2 center was dependent on the aldehyde used. In one case, the trans isomer was produced via reversible formation of the intermediate betaine, whereas in the alternative case, the C2 center was under Felkin Anh/Cornforth control through non-reversible formation of the betaine. Thus, the aldehyde stereocenter influenced the degree of reversibility in betaine formation, which impacted on the stereocontrol at the C2 position.

| S-EPMC1399452 | biostudies-literature

Rh-Catalyzed Conjugate Addition of Aryl and Alkenyl Boronic Acids to ?-Methylene-?-lactones: Stereoselective Synthesis of trans-3,4-Disubstituted ?-Lactones.

Project description:A one-step preparation of 3,4-disubstituted ?-lactones through Rh-catalyzed conjugate addition of aryl or alkenyl boronic acids to ?-methylene-?-lactones is described. The operationally simple, stereoselective transformation provides a broad range of ?-lactones from individual ?-methylene-?-lactone templates. This methodology allowed for a direct, final-step C-3 diversification of nocardiolactone, an antimicrobial natural product.

| S-EPMC5834916 | biostudies-literature

Enantioselective fluorescent recognition of chiral acids by cyclohexane-1,2-diamine-based bisbinaphthyl molecules.

Project description:The cyclohexane-1,2-diamine-based bisbinaphthyl macrocycles (S)-/(R)-5 and their cyclic and acyclic analogues are synthesized. The interactions of these compounds with various chiral acids are studied. Compounds (S)-/(R)-5 exhibit highly enantioselective fluorescent responses and high fluorescent sensitivity toward alpha-hydroxycarboxylic acids and N-protected amino acids. Among these interactions, (S)-mandelic acid (10(-3) M) led to over 20-fold fluorescence enhancement of (S)-5 (1.0 x 10(-5) M in benzene/0.05% DME) at the monomer emission, and (S)-hexahydromandelic acid (10(-3) M) led to over 80-fold fluorescence enhancement. These results demonstrate that (S)-5 is useful as an enantioselective fluorescent sensor for the recognition of the chiral acids. On the basis of the study of the structures of (S)-5 and the previously reported 1,2-diphenylethylenediamine-based bisbinaphthyl macrocycle (S)-4, the large fluorescence enhancement of (S)-5 with a chirality-matched alpha-hydroxycarboxylic acid is attributed to the formation of a structurally rigidified host-guest complex and the further interaction of this complex with the acid to suppress the photoinduced electron-transfer fluorescent quenching caused by the nitrogens in (S)-5.

| S-EPMC2536617 | biostudies-literature

Synthesis of chiral anti-1,2-diamine derivatives through copper(I)-catalyzed asymmetric α-addition of ketimines to aldimines.

Project description:Chiral 1,2-diamines serve as not only common structure units in bioactive molecules but also useful ligands for a range of catalytic asymmetric reactions. Here, we report a method to access anti-1,2-diamine derivatives. By means of the electron-withdrawing nature of 2- or 4-nitro-phenyl group, a copper(I)-catalyzed asymmetric α-addition of ketimines derived from trifluoroacetophenone and 2- or 4-NO2-benzylamines to aldimines is achieved, which affords a series of chiral anti-1,2-diamine derivatives in moderate to high yields with moderate to high diastereoselectivity and high to excellent enantioselectivity. Aromatic aldimines, heteroaromatic aldimines, and aliphatic aldimines serve as suitable substrates. The nitro group is demonstrated as a synthetical handle by several transformations, including a particularly interesting Fe(acac)3-catalyzed radical hydroamination with a trisubstituted olefin. Moreover, the aryl amine moiety obtained by the reduction of the nitro group serves as a synthetically versatile group, which leads to the generation of several functional groups by the powerful Sandmeyer reaction, such as -OH, -Br, -CF3, and -BPin.

| S-EPMC7479099 | biostudies-literature

Iron-Catalyzed Acceptorless Dehydrogenative Coupling of Alcohols With Aromatic Diamines: Selective Synthesis of 1,2-Disubstituted Benzimidazoles.

Project description:Benzimidazoles are important N-heteroaromatic compounds with various biological activities and pharmacological applications. Herein, we present the first iron-catalyzed selective synthesis of 1,2-disubstituted benzimidazoles via acceptorless dehydrogenative coupling of primary alcohols with aromatic diamines. The tricarbonyl (?4-cyclopentadienone) iron complex catalyzed dehydrogenative cyclization, releasing water and hydrogen gas as by-products. The earth abundance and low toxicity of iron metal enable the provision of an eco-friendly and efficient catalytic method for the synthesis of benzimidazoles.

| S-EPMC7317090 | biostudies-literature

CuH-Catalyzed Asymmetric Reduction of ?,?-Unsaturated Carboxylic Acids to ?-Chiral Aldehydes.

Project description:The copper hydride (CuH)-catalyzed enantioselective reduction of ?,?-unsaturated carboxylic acids to saturated aldehydes is reported. This protocol provides a new method to access a variety of ?-chiral aldehydes in good yields, with high levels of enantioselectivity and broad functional group tolerance. A reaction pathway involving a ketene intermediate is proposed based on preliminary mechanistic studies and density functional theory calculations.

| S-EPMC5800953 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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