Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Iridium-Catalyzed Diastereoselective and Enantioselective Allylic Substitutions with Acyclic ?-Alkoxy Ketones.

ABSTRACT: The asymmetric alkylation of acyclic ketones is a longstanding challenge in organic synthesis. Reported herein are diastereoselective and enantioselective allylic substitutions with acyclic ?-alkoxy ketones catalyzed by a metallacyclic iridium complex to form products with contiguous stereogenic centers derived from the nucleophile and electrophile. These reactions occur between allyl methyl carbonates and unstabilized copper(I) enolates generated in?situ from acyclic ?-alkoxy ketones. The resulting products can be readily converted into enantioenriched tertiary alcohols and tetrahydrofuran derivatives without erosion of enantiomeric purity.

SUBMITTER: Jiang X

PROVIDER: S-EPMC4969080 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Iridium-Catalyzed Diastereoselective and Enantioselective Allylic Substitutions with Acyclic α-Alkoxy Ketones.

Jiang Xingyu X Jiang Xingyu X Chen Wenyong W Hartwig John F JF

Angewandte Chemie (International ed. in English) 20160401 19

The asymmetric alkylation of acyclic ketones is a longstanding challenge in organic synthesis. Reported herein are diastereoselective and enantioselective allylic substitutions with acyclic α-alkoxy ketones catalyzed by a metallacyclic iridium complex to form products with contiguous stereogenic centers derived from the nucleophile and electrophile. These reactions occur between allyl methyl carbonates and unstabilized copper(I) enolates generated in situ from acyclic α-alkoxy ketones. The resul ...[more]

PMID: 27038004

Similar Datasets

Palladium-Catalyzed Enantioselective Decarboxylative Allylic Alkylation of Acyclic α-<i>N</i>-Pyrrolyl/Indolyl Ketones.

Project description:The synthesis of fully substituted α-N-pyrrolyl and indolyl ketones via enantioselective palladium-catalyzed allylic alkylation is described. The acyclic ketones are alkylated in high yields with high enantioselectivities through the use of an electron-deficient phosphinooxazoline ligand, furnishing a highly congested and synthetically challenging stereocenter. The obtained alkylation products contain multiple reactive sites poised for additional functionalizations and diversification.

| S-EPMC7608871 | biostudies-literature

Palladium-catalyzed asymmetric allylic alpha-alkylation of acyclic ketones.

Project description:The first example of Pd-catalyzed asymmetric allyl alkylation of the conformationally nonrigid acyclic ketone enolates is reported with excellent yields, regioselectivity, and enantioselectivity. The double bond geometry of the allyl enol carbonates affects its reactivity, selectivity, as well as the absolute configuration of the products. An opposite enantioselectivity from what is predicted by a direct attack of the enolate on the allyl moiety of the pi-ally-Pd complex was observed. An alternative mechanism was proposed, which involves an inner sphere process of coordination of the enolate to Pd followed by reductive elimination.

| S-EPMC2533158 | biostudies-literature

Iridium-catalyzed enantioselective allylic substitution of unstabilized enolates derived from ?,?-unsaturated ketones.

Project description:We report Ir-catalyzed, enantioselective allylic substitution reactions of unstabilized silyl enolates derived from ?,?-unsaturated ketones. Asymmetric allylic substitution of a variety of allylic carbonates with silyl enolates gave allylated products in 62-94% yield with 90-98% ee and >20:1 branched-to-linear selectivity. The synthetic utility of this method was illustrated by the short synthesis of an anticancer agent, TEI-9826.

| S-EPMC4159307 | biostudies-literature

Enantioselective Synthesis of Acyclic ?-Quaternary Carboxylic Acid Derivatives through Iridium-Catalyzed Allylic Alkylation.

Project description:The first highly enantioselective iridium-catalyzed allylic alkylation that provides access to products bearing an allylic all-carbon quaternary stereogenic center has been developed. The reaction utilizes a masked acyl cyanide (MAC) reagent, which enables the one-pot preparation of ?-quaternary carboxylic acids, esters, and amides with a high degree of enantioselectivity. The utility of these products is further explored through a series of diverse product transformations.

| S-EPMC5674796 | biostudies-literature

Enantioselective Pd-Catalyzed Decarboxylative Allylic Alkylation of Thiopyranones. Access to Acyclic, Stereogenic ?-Quaternary Ketones.

Project description:A catalytic, enantioselective decarboxylative allylic alkylation of 4-thiopyranones is reported. The ?-quaternary 4-thiopyranones produced are challenging to access by standard enolate alkylation owing to facile ring-opening ?-sulfur elimination. In addition, reduction of the carbon-sulfur bonds provides access to elusive acyclic ?-quaternary ketones. The alkylated products are obtained in up to 92% yield and 94% enantiomeric excess.

| S-EPMC5632216 | biostudies-literature

Iridium-Catalyzed Regio- and Enantioselective Allylic Substitution of Trisubstituted Allylic Electrophiles.

Project description:The first Ir-catalyzed enantioselective allylation of trisubstituted allylic electrophiles has been developed. Through modification of the leaving group of allylic electrophiles, we found that trisubstituted allylic phosphates are suitable electrophiles for asymmetric allylation. The reaction of allylic phosphates with enol silanes derived from dioxinones gave allylated products in good yields with high enantioselectivities.

| S-EPMC5213737 | biostudies-literature

Enantioselective Nickel-Catalyzed anti-Arylmetallative Cyclizations onto Acyclic Ketones.

Project description:Domino reactions involving nickel-catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary-alcohol-containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti-arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.

| S-EPMC8048927 | biostudies-literature

Iridium-catalyzed enantioselective direct vinylogous allylic alkylation of coumarins.

Project description:The first iridium-catalyzed enantioselective vinylogous allylic alkylation of coumarins is presented. Using easily accessible linear allylic carbonates as the allylic electrophile, this reaction installs unfunctionalized allyl groups at the ?-position of 4-methylcoumarins in an exclusively branched-selective manner generally in high yields with an excellent level of enantioselectivity (up to 99?:?1 er).

| S-EPMC6050583 | biostudies-literature

Iridium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of 1,3-Disubstituted Isoquinolines.

Project description:The development of a general method utilizing a hydroxymethyl directing group for asymmetric hydrogenation of 1,3-disubstituted isoquinolines to provide chiral 1,2,3,4-tetrahydroisoquinolines is reported. The reaction, which utilizes [Ir(cod)Cl]2 and a commercially available chiral xyliphos ligand, proceeds in good yield with high levels of enantioselectivity and diastereo-selectivity (up to 95% ee and >20:1 dr) on a range of differentially substituted isoquinolines. Directing group studies demonstrate that the hydroxymethyl functional group at the C1-position is more efficient at enabling hydrogenation than other substituents, although high levels of enantioselectivity were conserved across a variety of polar and non-polar functional groups. By utilizing the generated chiral β-amino alcohol as a functional handle, the synthetic utility is further highlighted via the synthesis of 1,2-fused oxazolidine, oxazolidinone, and morpholinone tetrahydroisoquinolines in one step. Additionally, a non-natural analog of the tetrahydroprotoberberine alkaloids was successfully synthesized.

| S-EPMC8152574 | biostudies-literature

Enantio-, diastereo-, and regioselective iridium-catalyzed asymmetric allylic alkylation of acyclic ?-ketoesters.

Project description:The first regio-, diastereo-, and enantioselective allylic alkylation of acyclic ?-ketoesters to form vicinal tertiary and all-carbon quaternary stereocenters is reported. Critical to the successful development of this method was the employment of iridium catalysis in concert with N-aryl-phosphoramidite ligands. Broad functional group tolerance is observed at the keto-, ester-, and ?-positions of the nucleophile. Various transformations demonstrating the utility of this method for rapidly accessing complex enantioenriched compounds are reported.

| S-EPMC3881553 | 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