Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Homoallylic amines by reductive inter- and intramolecular coupling of allenes and nitriles.

ABSTRACT: The one-pot hydrozirconation of allenes and nitriles followed by an in situ transmetalation of the allylzirconocene with dimethylzinc or zinc chloride provides functionalized homoallylic amines. An intramolecular version of this process leads to 3-aminotetrahydrofurans and 3-aminotetrahydropyrans.

SUBMITTER: Wipf P

PROVIDER: S-EPMC3135093 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Preparation of stereodefined homoallylic amines from the reductive cross-coupling of allylic alcohols with imines.

Project description:Regio-, diastereo-, and enantioselective coupling reactions between imines and allylic alcohols have been developed. These coupling reactions deliver complex homoallylic amine products through a convergent C-C bond forming process that does not proceed through intermediate allylic organometallic reagents. In general, convergent coupling, by exposure of an allylic alkoxide to a preformed Ti-imine complex, occurs with allylic transposition in a predictable and stereocontrolled manner. While simple diastereoselection in these reactions is high, delivering anti-products with ?20:1 selectivity, the organometallic transformation described is compatible with a diverse range of functionality and substrates (including aliphatic and aromatic imines, allylic silanes, trisubstituted alkenes, vinyl- and aryl halides, trifluoromethyl groups, thioethers, and aromatic heterocycles). Alkene geometry of the products is a complex function of the allylic alcohol structure and is consistent with a mechanistic proposal based on syn-carbometalation followed by syn-elimination by way of a boat-like transition state geometry. Single asymmetric coupling reactions provide a means to translate the stereochemical information of the allylic alcohol to the homoallylic amine or to control diastereoselection in the coupling reactions of achiral allylic alcohols with chiral imines. Double asymmetric coupling reactions are also described that afford a unique means to control stereoselection in these complex convergent coupling processes. Finally, empirical models are proposed that are consistent with the observed stereochemical course of these coupling reactions en route to chiral homoallylic amines possessing di- or trisubstituted alkenes and anti- or syn- relative stereochemistry at the allylic and homoallylic positions.

| S-EPMC2993781 | biostudies-literature

Enantioselective and site-specific copper-catalyzed reductive allyl-allyl cross-coupling of allenes.

Project description:A copper-catalyzed asymmetric reductive allyl-allyl cross-coupling reaction of allenes with allylic phosphates wherein allenes were used as allylmetal surrogates has been achieved for the first time. This protocol provides an efficient and straightforward route to optically active 1,5-dienes in a highly enantioselective and site-specific fashion. Furthermore, all-carbon quaternary stereogenic centers could also be constructed with this protocol. The versatility of the products is demonstrated through a diverse array of further transformations of the enantioenriched 1,5-dienes.

| S-EPMC6369434 | biostudies-literature

Polyketide assembly by alkene-alkyne reductive cross-coupling: spiroketals through the union of homoallylic alcohols.

Project description:A reaction sequence composed of regioselective formal hydroalkynylation, reductive ene-yne cross-coupling, and oxidative cyclization has been developed to prepare stereochemically dense spiroketals. Overall, the chemistry defines a three-component coupling process for the union of two homoallylic alcohol-based substrates with trimethylsilylacetylene.

| S-EPMC2892691 | biostudies-literature

Secondary amines as coupling partners in direct catalytic asymmetric reductive amination.

Project description:The secondary amine participating asymmetric reductive amination remains an unsolved problem in organic synthesis. Here we show for the first time that secondary amines are capable of effectively serving as N-sources in direct asymmetric reductive amination to afford corresponding tertiary chiral amines with the help of a selected additive set under mild conditions (0-25 °C). The applied chiral phosphoramidite ligands are readily prepared from BINOL and easily modified. Compared with common tertiary chiral amine synthetic methods, this procedure is much more concise and scalable, as exemplified by the facile synthesis of rivastigmine and N-methyl-1-phenylethanamine.

| S-EPMC6482873 | biostudies-literature

Intramolecular anodic olefin coupling reactions and the synthesis of cyclic amines.

Project description:Anodic olefin coupling reactions using a tosylamine trapping group have been studied. The cyclizations are favored by the use of a less-polar radical cation and more basic reaction conditions. The most significant factor for obtaining good yields of cyclic product is the use of the more basic reaction conditions. However, a number of factors including the nature of both the solvent and the electrolyte used can influence the yield of the cyclizations. The cyclizations allow for the rapid synthesis of both substituted proline and pipecolic acid type derivatives.

| S-EPMC3950632 | biostudies-literature

Ruthenium catalyzed reductive coupling of paraformaldehyde to trifluoromethyl allenes: CF3-bearing all-carbon quaternary centers.

Project description:Trifluoromethyl substituted allenes engage in ruthenium catalyzed reductive couplings with paraformaldehyde to form products of hydrohydroxymethylation as single regioisomers. This method enables generation of CF3-bearing all-carbon quaternary stereocenters.

| S-EPMC3779475 | biostudies-literature

Rapid Asymmetric Synthesis of Disubstituted Allenes by Coupling of Flow-Generated Diazo Compounds and Propargylated Amines.

Project description:We report herein the asymmetric coupling of flow-generated unstabilized diazo compounds and propargylated amine derivatives, using a new pyridinebis(imidazoline) ligand, a copper catalyst and base. The reaction proceeds rapidly, generating chiral allenes in 10-20 minutes with high enantioselectivity (89-98 % de/ee), moderate yields and a wide functional group tolerance.

| S-EPMC5363227 | biostudies-literature

Copper-Catalyzed Borylative Cross-Coupling of Allenes and Imines: Selective Three-Component Assembly of Branched Homoallyl Amines.

Project description:A copper-catalyzed three-component coupling of allenes, bis(pinacolato)diboron, and imines allows regio-, chemo-, and diastereoselective assembly of branched ?,?-substituted-?-boryl homoallylic amines, that is, products bearing versatile amino, alkenyl, and borane functionality. Alternatively, convenient oxidative workup allows access to ?-substituted-?-amino ketones. A computational study has been used to probe the stereochemical course of the cross-coupling.

| S-EPMC4736445 | biostudies-literature

(4+1) vs (4+2): Catalytic Intramolecular Coupling between Cyclobutanones and Trisubstituted Allenes via C-C Activation.

Project description:Herein we describe a rhodium-catalyzed (4+1) cyclization between cyclobutanones and allenes, which provides a distinct [4.2.1]-bicyclic skeleton containing two quaternary carbon centers. The reaction involves C-C activation of cyclobutanones and employs allenes as a one-carbon unit. A variety of functional groups can be tolerated, and a diverse range of polycyclic scaffolds can be accessed. Excellent enantioselectivity can be obtained, which is enabled by a TADDOL-derived phosphoramidite ligand. The bridged bicyclic products can be further functionalized or derivatized though simple transformations.

| S-EPMC4884657 | biostudies-literature

Intermolecular Hydroamination of 1,3-Dienes To Generate Homoallylic Amines.

Project description:We report a Rh-catalyzed hydroamination of 1,3-dienes to generate homoallylic amines. Our work showcases the first case of anti-Markovnikov selectivity in the intermolecular coupling of amines and 1,3-dienes. By tuning the ligand properties and Brønsted acid additive, we find that a combination of rac-BINAP and mandelic acid is critical for achieving anti-Markovnikov selectivity.

| S-EPMC6563820 | 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