Browse
Submit Data
Databases
API
Help

Dataset Information

34 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

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

ABSTRACT: 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.

SUBMITTER: Shockley SE

PROVIDER: S-EPMC5674796 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

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

Shockley Samantha E SE Hethcox J Caleb JC Stoltz Brian M BM

Angewandte Chemie (International ed. in English) 20170809 38

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 α-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. ...[more]

PMID: 28722280

Similar Datasets

Enantioselective Synthesis of Vicinal All-Carbon Quaternary Centers via Iridium-Catalyzed Allylic Alkylation.

Project description:The development of the first enantioselective transition-metal-catalyzed allylic alkylation providing access to acyclic products bearing vicinal all-carbon quaternary centers is disclosed. The iridium-catalyzed allylic alkylation reaction proceeds with excellent yields and selectivities for a range of malononitrile-derived nucleophiles and trisubstituted allylic electrophiles. The utility of these sterically congested products is explored through a series of diverse chemo- and diastereoselective product transformations to afford a number of highly valuable, densely functionalized building blocks, including those containing vicinal all-carbon quaternary stereocenters.

| S-EPMC6033654 | biostudies-literature

Catalytic Enantioselective Synthesis of Acyclic Quaternary Centers: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Acyclic Enol Carbonates.

Project description:The first enantioselective palladium-catalyzed decarboxylative allylic alkylation of fully substituted acyclic enol carbonates providing linear ?-quaternary ketones is reported. Investigation into the reaction revealed that the use of an electron-deficient phosphinooxazoline ligand renders the enolate geometry of the starting material inconsequential, with the same enantiomer of product obtained in the same level of selectivity regardless of the starting ratio of enolates. As a result, a general method toward acyclic all-carbon quaternary stereocenters has been developed.

| S-EPMC6103296 | 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 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

Enantioselective Construction of Acyclic Quaternary Carbon Stereocenters: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Amide Enolates.

Project description:We report a divergent and modular protocol for the preparation of acyclic molecular frameworks containing newly created quaternary carbon stereocenters. Central to this approach is a sequence composed of a (1) regioselective and -retentive preparation of allyloxycarbonyl-trapped fully substituted stereodefined amide enolates and of a (2) enantioselective palladium-catalyzed decarboxylative allylic alkylation reaction using a novel bisphosphine ligand.

| S-EPMC5555155 | biostudies-literature

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

Project description: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.

| S-EPMC4969080 | 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

Enantioselective synthesis of highly oxygenated acyclic quaternary center-containing building blocks <i>via</i> palladium-catalyzed decarboxylative allylic alkylation of cyclic siloxyketones.

Project description:The development of a palladium-catalyzed enantioselective decarboxylative allylic alkylation of cyclic siloxyketones to produce enantioenriched silicon-tethered heterocycles is reported. The reaction proceeds smoothly to provide products bearing a quaternary stereocenter in excellent yields (up to 91% yield) with high levels of enantioselectivity (up to 94% ee). We further utilized the unique reactivity of the siloxy functionality to access chiral, highly oxygenated acyclic quaternary building blocks. In addition, we subsequently demonstrated the utility of these compounds through the synthesis of a lactone bearing vicinal quaternary-trisubstituted stereocenters.

| S-EPMC8162308 | biostudies-literature

Enantioselective synthesis of α-quaternary Mannich adducts by palladium-catalyzed allylic alkylation: total synthesis of (+)-sibirinine.

Project description:A catalytic enantioselective method for the synthesis of α-quaternary Mannich-type products is reported. The two-step sequence of (1) Mannich reaction followed by (2) decarboxylative enantioselective allylic alkylation serves as a novel strategy to in effect access asymmetric Mannich-type products of "thermodynamic" enolates of substrates possessing additional enolizable positions and acidic protons. Palladium-catalyzed decarboxylative allylic alkylation enables the enantioselective synthesis of five-, six-, and seven-membered ketone, lactam, and other heterocyclic systems. The mild reaction conditions are notable given the acidic free N-H groups and high functional group tolerance in each of the substrates. The utility of this method is highlighted in the first total synthesis of (+)-sibirinine.

| S-EPMC4311947 | biostudies-literature

Iridium-catalyzed enantioselective olefinic C(sp<sup>2</sup>)-H allylic alkylation.

Project description:The first iridium-catalyzed enantioselective olefinic C(sp2)-H allylic alkylation is developed in cooperation with Lewis base catalysis. This reaction, catalyzed by cinchonidine and an in situ generated cyclometalated Ir(i)/phosphoramidite complex, makes use of the latent enolate character of an α,β-unsaturated carbonyl compound, namely coumalate ester, to introduce an allyl group at its α-position in a branched-selective manner in moderate to good yield with good to excellent enantioselectivities (up to 98 : 2 er).

| S-EPMC8179414 | 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