Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Lewis base catalyzed, enantioselective, intramolecular sulfenoamination of olefins.

ABSTRACT: A method for the enantioselective, intramolecular sulfenoamination of various olefins has been developed using a chiral BINAM-based selenophosphoramide, Lewis base catalyst. Terminal and trans disubstituted alkenes afforded pyrrolidines, piperidines, and azepanes in high yields and high enantiomeric ratios via enantioselective formation and subsequent stereospecific capture of the thiiranium intermediate with the pendant tosyl-protected amine.

SUBMITTER: Denmark SE

PROVIDER: S-EPMC4073881 | biostudies-other | 2014 Jun

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Lewis base catalyzed, enantioselective, intramolecular sulfenoamination of olefins.

Denmark Scott E SE Chi Hyung Min HM

Journal of the American Chemical Society 20140613 25

A method for the enantioselective, intramolecular sulfenoamination of various olefins has been developed using a chiral BINAM-based selenophosphoramide, Lewis base catalyst. Terminal and trans disubstituted alkenes afforded pyrrolidines, piperidines, and azepanes in high yields and high enantiomeric ratios via enantioselective formation and subsequent stereospecific capture of the thiiranium intermediate with the pendant tosyl-protected amine. ...[more]

PMID: 24926794

Similar Datasets

Enantioselective, Lewis Base-Catalyzed Sulfenocyclization of Polyenes.

Project description:A sulfenium-ion-initiated, catalytic, enantioselective polyene cyclization is described. Homogeranylarenes and ortho-geranylphenols undergo polycyclization in good yield, diastereoselectivity, and enantioselectivity. The stereodetermining step is the generation of an enantiomerically enriched thiiranium ion from a terminal alkene and a sulfenylating agent in the presence of a chiral Lewis basic catalyst. The use of hexafluoroisopropyl alcohol as the solvent is crucial to obtain good yields. The thioether moiety resulting from the reaction can be subsequently transformed into diverse oxygen and carbon functionality postcyclization. The utility of this method is demonstrated by the enantioselective syntheses of (+)-ferruginol and (+)-hinokiol.

| S-EPMC6008787 | biostudies-literature

Enantioselective Lewis Acid Catalyzed ortho Photocycloaddition of Olefins to Phenanthrene-9-carboxaldehydes.

Project description:Visible-light irradiation (?=457?nm) enabled the enantioselective ortho photocycloaddition of olefins to phenanthrene-9-carboxaldehydes (15 examples, 46-93?% yield, 82-98?% ee). A chiral oxazaborolidine Lewis acid (20?mol?%) was employed as the catalyst. It operates by coordination to the aldehyde inducing a bathochromic absorption shift beyond the n?* absorption of the uncomplexed aldehyde. At long wavelengths the Lewis acid complex is exclusively excited; within the complex, one enantiotopic face of the aromatic aldehyde is efficiently shielded. Lewis acid coordination also alters the type selectivity and the simple diastereoselectivity of the photocycloaddition.

| S-EPMC6220838 | biostudies-other

Enantioselective Crossed Photocycloadditions of Styrenic Olefins by Lewis Acid Catalyzed Triplet Sensitization.

Project description:The synthesis of unsymmetrical cyclobutanes by controlled heterodimerization of olefins remains a substantial challenge, particularly in an enantiocontrolled fashion. Shown herein is that chiral Lewis acid catalyzed triplet sensitization enables the synthesis of highly enantioenriched diarylcyclobutanes by photocycloaddition of structurally varied 2'-hydroxychalcones with a range of styrene coupling partners. The utility of this reaction is demonstrated through the direct synthesis of a representative norlignan cyclobutane natural product.

| S-EPMC5661956 | biostudies-literature

Catalytic, enantioselective, intramolecular carbosulfenylation of olefins.

Project description:The first catalytic, enantioselective carbosulfenylation of alkenes with an aromatic nucleophile is described, using a BINAM-based selenophosphoramide catalyst. E-Alkyl- and aryl-substituted alkenes afforded tetrahydronaphthalenes with complete diastereospecificity, and generally high enantiomeric ratios.

| S-EPMC3675264 | biostudies-literature

A dual Lewis base activation strategy for enantioselective carbene-catalyzed annulations.

Project description:A dual activation strategy integrating N-heterocyclic carbene (NHC) catalysis and a second Lewis base has been developed. NHC-bound homoenolate equivalents derived from ?,?-unsaturated aldehydes combine with transient reactive o-quinone methides in an enantioselective formal [4 + 3] fashion to access 2-benzoxopinones. The overall approach provides a general blueprint for the integration of carbene catalysis with additional Lewis base activation modes.

| S-EPMC3746556 | biostudies-literature

Enantioselective, Lewis Base-Catalyzed Carbosulfenylation of Alkenylboronates by 1,2-Boronate Migration.

Project description:A catalytic, enantioselective method for the preparation of chiral, non-racemic, alkylboronic esters bearing two vicinal stereogenic centers is described. The reaction proceeds via a 1,2-migration of a zwitterionic thiiranium-boronate complex to give exclusively anti carbosulfenylation products. A broad scope of aryl groups migrate with good yield and excellent enantioselectivity (up to 99:1 e.r.). Similarly, a range of di- and trisubstituted alkenylboronic esters are competent reaction partners. This method provides access to both secondary and tertiary chiral alkylboronic esters.

| S-EPMC6345169 | biostudies-literature

Enantioselective Synthesis of ?-Lactams by Lewis Base Catalyzed Sulfenoamidation of Alkenes.

Project description:A method for the catalytic, enantioselective, intramolecular 1,2-sulfenoamidation of alkenes is described. Lewis base activation of a suitable sulfur electrophile generates an enantioenriched, thiiranium ion intermediate from a ?,?-unsaturated sulfonyl carboxamide. This intermediate is subsequently intercepted by the sulfonamide nitrogen resulting in cyclization to form ?-lactams. Electron-poor alkenes required the use of a new selenophosphoramidate Lewis base catalyst. Subsequent manipulations of the products harness the latent reactivity of both the amide and thioether functionality.

| S-EPMC7127933 | biostudies-literature

Enzyme-Catalyzed Intramolecular Enantioselective Hydroalkoxylation.

Project description:Hydroalkoxylation is a powerful and efficient method of forming C-O bonds and cyclic ethers in synthetic chemistry. In studying the biosynthesis of the fungal natural product herqueinone, we identified an enzyme that can perform an intramolecular enantioselective hydroalkoxylation reaction. PhnH catalyzes the addition of a phenol to the terminal olefin of a reverse prenyl group to give a dihydrobenzofuran product. The enzyme accelerates the reaction by 3 × 105-fold compared to the uncatalyzed reaction. PhnH belongs to a superfamily of proteins with a domain of unknown function (DUF3237), of which no member has a previously verified function. The discovery of PhnH demonstrates that enzymes can be used to promote the enantioselective hydroalkoxylation reaction and form cyclic ethers.

| S-EPMC5474393 | biostudies-literature

Structural, Mechanistic, Spectroscopic, and Preparative Studies on the Lewis Base Catalyzed, Enantioselective Sulfenofunctionalization of Alkenes.

Project description:The full details of mechanistic investigation on enantioselective sulfenofunctionalization of alkenes under Lewis base catalysis are described. Solution spectroscopic identification of the catalytically active sulfenylating agent has been accomplished along with the spectroscopic identification of putative thiiranium ion intermediates generated in the enantiodetermining step. The structural insights gleaned from these studies informed the design of new catalyst architectures to improve enantioselectivity. In addition, structural modification of the sulfenylating agents had a significant and salutary effect on the enantioselectivity of sulfenofunctionalization which was demonstrated to be general for trans disubstituted alkenes. Whereas electronic modulation had little effect on the rate and selectivity, steric bulk on arylsulfenylphthalimides was very beneficial.

| S-EPMC5755611 | biostudies-literature

Catalytic, enantioselective, intramolecular carbosulfenylation of olefins. Preparative and stereochemical aspects.

Project description:The first catalytic, enantioselective, intramolecular carbosulfenylation of isolated alkenes with aromatic nucleophiles is described. The combination of N-phenylsulfenylphthalimide, a chiral selenophosphoramide derived from BINAM, and ethanesulfonic acid as a cocatalytic Brønsted acid induced an efficient and selective cyclofunctionalization of various alkenes (aliphatic and aromatic) tethered to a 3,4-methylenedioxyphenyl ring. Under these conditions, 6-phenylthio-5,6,7,8-tetrahydronaphthalenes are formed diastereospecifically in good yields (50-92%) and high enantioselectivities (71:29-97:3 er). E-Alkenes reacted much more rapidly and with much higher selectivity than Z-alkenes, whereas electron-rich alkenes reacted more rapidly but with comparable selectivity to electron-neutral alkenes and electron-deficient alkenes. The Brønsted acid played a critical role in effecting reproducible enantioselectivity. A model for the origin of enantioselectivity and the dependence of rate and selectivity on alkene structure is proposed along with a rationale for the site selectivity in reactions with monoactivated arene nucleophiles.

| S-EPMC3913010 | 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