Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Preparation of Distant Quaternary Carbon Stereocenters by Double Selective Ring-Opening of 1,1-Biscyclopropyl Methanol Derivatives.

ABSTRACT: The diastereoselective double carbometalation reaction of cyclopropenes provides, in a single-pot operation, two ω-ene-[1,1]-bicyclopropyl ester derivatives. One regioisomer then undergoes a Pd-catalyzed addition of aryl iodide to provide skipped dienes possessing several distant stereocenters including two congested quaternary carbon centers with excellent diastereoselectivity.

SUBMITTER: Siddaraju Y

PROVIDER: S-EPMC9401570 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Preparation of Distant Quaternary Carbon Stereocenters by Double Selective Ring-Opening of 1,1-Biscyclopropyl Methanol Derivatives.

Siddaraju Yogesh Y Sabbatani Juliette J Cohen Anthony A Marek Ilan I

Angewandte Chemie (International ed. in English) 20220520 28

The diastereoselective double carbometalation reaction of cyclopropenes provides, in a single-pot operation, two ω-ene-[1,1]-bicyclopropyl ester derivatives. One regioisomer then undergoes a Pd-catalyzed addition of aryl iodide to provide skipped dienes possessing several distant stereocenters including two congested quaternary carbon centers with excellent diastereoselectivity. ...[more]

PMID: 35521738

Similar Datasets

Stereospecific Construction of Quaternary Carbon Stereocenters from Quaternary Carbon Stereocenters.

Project description:Organoaluminum species promote a smooth nucleophilic substitution at the quaternary carbon stereocenter of stereodefined polysubstituted cyclopropyl methyl phosphate with a complete inversion of configuration, even when more reactive functional groups are present. The regio- and diastereoselectivity of the substitution is attributed to the existence of a bicyclobutonium intermediate.

| S-EPMC9052742 | biostudies-literature

Stereodivergent synthesis of vicinal quaternary-quaternary stereocenters and bioactive hyperolactones.

Project description:Although great success has been achieved in asymmetric Claisen rearrangement for the synthesis of chiral γ,δ-unsaturated carbonyl compounds bearing vicinal tertiary-quaternary stereocenters, the development of asymmetric versions for stereodivergent construction of adjacent quaternary-quaternary stereocenters remains a formidable challenge because of the high steric hindrance. Here we report a catalytic enantioselective dearomatization Claisen rearrangement of allyl furyl ethers catalyzed by chiral N,N'-dioxide-NiII complex catalysts. A variety of chiral γ,δ-unsaturated carbonyl compounds bearing vicinal quaternary-quaternary stereocenters were obtained with excellent outcomes under mild conditions. Furthermore, we disclosed that by matching the configuration of the catalysts and the alkene unit of the substrates, four stereoisomers of the products could be prepared in excellent yields and stereoselectivities. Finally, the fascination of this strategy was demonstrated by stereodivergent synthesis of bioactive natural products hyperolactones B, C, and their epimers. A possible catalytic model was proposed to explain the origin of the asymmetric induction.

| S-EPMC5958103 | biostudies-literature

Preparation and ring-opening reactions of N-diphenylphosphinyl vinyl aziridines.

Project description:Predominantly (E)-N-diphenylphosphinyl vinyl aziridines are prepared by a reaction of N-diphenylphosphinyl imines with ?-bromoallyllithium in the presence of freshly fused ZnCl2. These aziridines undergo a ring-opening reaction with a variety of carbon and heteronucleophiles, in good yield, and generally with good regioselectivity.

| S-EPMC3678660 | biostudies-literature

Synthesis of β<sup>2,2</sup>-Amino Acids by Stereoselective Alkylation of Isoserine Derivatives Followed by Nucleophilic Ring Opening of Quaternary Sulfamidates.

Project description:Chiral bicyclic N,O-acetal isoserine derivatives have been synthesized by an acid-catalyzed tandem N,O-acetalization/intramolecular transcarbamoylation reaction between conveniently protected l-isoserine and 2,2,3,3-tetramethoxybutane. The delicate balance of the steric interactions between the different functional groups on each possible diastereoisomer controls their thermodynamic stability and hence the experimental product distribution. These chiral isoserine derivatives undergo diastereoselective alkylation at the α position, proceeding with either retention or inversion of the configuration depending on the relative configuration of the stereocenters. Quantum mechanical calculations revealed that a concave-face alkylation is favored due to smaller torsional and steric interactions at the bicyclic scaffold. This synthetic methodology gives access to chiral β2,2-amino acids, attractive compounds bearing a quaternary stereocenter at the α position with applications in peptidomimetic and medicinal chemistry. Thus, enantiopure α-alkylisoserine derivatives were produced upon acidic hydrolysis of these alkylated scaffolds. In addition, α-benzylisoserine was readily transformed into a five-membered ring cyclic sulfamidate, which was ring opened regioselectively with representative nucleophiles to yield other types of enantiopure β2,2-amino acids such as α-benzyl-α-heterofunctionalized-β-alanines and α-benzylnorlanthionine derivatives.

| S-EPMC9490828 | biostudies-literature

Selective preparation of tetrasubstituted fluoroalkenes by fluorine-directed oxetane ring-opening reactions.

Project description:The selective ring-opening reaction of fluoroalkylidene-oxetanes was directed by the presence of the fluorine atom, enabling a two-step access to tetrasubstituted fluoroalkenes with excellent geometry control. Despite its small van der Waals radii electronic, rather than steric influences of the fluorine atom governed the ring-opening reaction with bromide ions, even in the presence of bulky substituents.

| S-EPMC7418098 | biostudies-literature

Enantioselective Formation of CF<sub>3</sub>-Bearing All-Carbon Quaternary Stereocenters via C-H Functionalization of Methanol: Iridium Catalyzed Allene Hydrohydroxymethylation.

Project description:Using an iridium catalyst modified by PhanePhos, CF3-allenes react with methanol to form branched products of hydrohydroxymethylation as single regioisomers with excellent levels of enantiomeric enrichment. This hydrogen autotransfer process enables catalytic enantioselective formation of acyclic CF3-bearing all-carbon quaternary stereocenters in the absence of stoichiometric metals or byproducts.

| S-EPMC5651675 | biostudies-literature

Synthesis of Indole Derivatives via Aryl Triazole Ring-Opening and Subsequent Cyclization.

Project description:A metal-free two-step synthetic approach for obtaining indole derivatives from aryl triazole fragment-containing compounds has been developed. In the first step, the Dimroth equilibrium, followed by nitrogen extrusion, Wolff rearrangement, and amine nucleophile addition, leads to the formation of N-aryl ethene-1,1-diamines. In the second step, the latter intermediates are cyclized into the target 1H-indoles in the presence of iodine. The developed method ensures the synthesis of indoles that possess N-substituents at the indole C2 position. Depending on the applied N-nucleophile, the indolization step provides a selectivity either towards 1H-indoles or 1-aryl-1H-indoles.

| S-EPMC11767399 | biostudies-literature

A Facile Oxidative Opening of the C-Ring in Luotonin A and Derivatives.

Project description:An oxidative ring opening reaction of the central ring C in the alkaloid Luotonin A and two of its derivatives was found to occur upon heating with an excess amine and potassium carbonate in dimethylsulfoxide (DMSO) solution in the presence of air oxygen. The structure of the novel amide-type products was elucidated and a possible mechanism for this reaction is proposed. Four of the new compounds show moderate in vitro anticancer activity towards human colon adenocarcinoma cells.

| S-EPMC6151605 | biostudies-literature

Enantioselective Nickel-Catalyzed Mizoroki-Heck Cyclizations To Generate Quaternary Stereocenters.

Project description:The development of enantioselective carbon-carbon bond couplings catalyzed by nonprecious metals is highly desirable in terms of cost efficiency and sustainability. The first nickel-catalyzed enantioselective Mizoroki-Heck coupling is reported. This transformation is accomplished via mild reaction conditions, leveraging on QuinoxP* as a chiral ligand to afford oxindoles containing quaternary stereocenters. Good reactivity and selectivity are observed in the presence of various functional groups. Computational studies suggest that the oxidative addition assembles an atropisomeric intermediate responsible for the facial selectivity of the insertion step.

| S-EPMC5634709 | biostudies-literature

1,1'-Dimethyl-1,1'-(butane-1,4-di-yl)dipyrrolidinium dibromide methanol disolvate.

Project description:In the title compound, C(14)H(30)N(2) (2+)·2Br(-)·2CH(3)OH, two terminal C atoms of the butane chain are connected to two N atoms of the 1-methyl-pyrollidines, forming a linear diquaternary ammonium cation. The cation lies across a centre of inversion located between the two central C atoms of the butane chain. The asymmetric unit therefore comprises one half-cation, a bromide anion and a methanol solvent mol-ecule. In the crystal structure, the bromide anions are linked to the methanol solvent mol-ecules by O-H⋯Br hydrogen bonds.

| S-EPMC2960454 | 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