Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Regio- and stereoselective cross-coupling of substituted olefins and imines. A convergent stereoselective synthesis of saturated 1,5-amino-alcohols and substituted piperidines.

ABSTRACT:

SUBMITTER: Takahashi M

PROVIDER: S-EPMC2732432 | biostudies-literature | 2007 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Regio- and stereoselective cross-coupling of substituted olefins and imines. A convergent stereoselective synthesis of saturated 1,5-amino-alcohols and substituted piperidines.

Takahashi Masayuki M Micalizio Glenn C GC

Journal of the American Chemical Society 20070526 24

PMID: 17530760

Similar Datasets

Regio- and Diastereoselective Synthesis of Highly Substituted, Oxygenated Piperidines from Tetrahydropyridines.

Project description:Diastereoselective epoxidation and regioselective ring-opening methods were developed for the synthesis of densely substituted, oxygenated piperidines from two classes of tetrahydropyridines with distinct stereochemical displays of functionalities. A new and practical in situ prepared epoxidation reagent was developed for the diastereoselective epoxidation of one class of sterically hindered tetrahydropyridines. The novel bifunctional epoxidation reagent, 2-carboperoxy-3,4,5,6-tetrafluorobenzoic acid, was designed to incorporate highly reactive percarboxy acid and pendant carboxylic acid groups, which through hydrogen bonding to the amino group successfully overrode steric effects and directed epoxidation to occur at the more hindered face of the tetrahydropyridine. Nucleophilic ring-opening of the epoxides with water, alcohols, and HF proceeded with high regioselectivity, affording piperidinol products with adjacent tetrasubstituted carbons.

| S-EPMC4496584 | biostudies-literature

A convergent stereoselective synthesis of quinolizidines and indolizidines: chemoselective coupling of 2-hydroxymethyl-substituted allylic silanes with imines.

Project description:A convergent synthesis of stereodefined indolizidines and quinolizidines through chemoselective allyl transfer between 2-hydroxymethyl-substituted allylic silanes and imines is described. Overall, highly substituted heterocycles that contain three stereogenic centers and up to four fused rings can be accessed in two steps from relatively simple coupling partners.

| S-EPMC2818501 | biostudies-literature

Regio- and Stereoselective Thianthrenation of Olefins To Access Versatile Alkenyl Electrophiles.

Project description:Herein, we report a regioselective alkenyl electrophile synthesis from unactivated olefins that is based on a direct and regioselective C-H thianthrenation reaction. The selectivity is proposed to arise from an unusual inverse-electron-demand hetero-Diels-Alder reaction. The alkenyl sulfonium salts can serve as electrophiles in palladium- and ruthenium-catalyzed cross-coupling reactions to make alkenyl C-C, C-Cl, C-Br, and C-SCF3 bonds with stereoretention.

| S-EPMC7154751 | biostudies-literature

Regio- and stereoselective 1,2-dihydropyridine alkylation/addition sequence for the synthesis of piperidines with quaternary centers.

Project description:The first example of C alkylation of 1,2-dihydropyridines with alkyl triflates and Michael acceptors was developed to introduce quaternary carbon centers with high regio- and diastereoselectivity. Hydride or carbon nucleophile addition to the resultant iminium ion also proceeded with high diastereoselectivity. Carbon nucleophile addition results in an unprecedented level of substitution to provide piperidine rings with adjacent tetrasubstituted carbon atoms.

| S-EPMC4058641 | biostudies-literature

Ruthenium(II)-Catalyzed Regio- and Stereoselective C-H Allylation of Indoles with Allyl Alcohols.

Project description:A ruthenium-catalyzed C-H allylation of indoles with allyl alcohols via β-hydroxide elimination is reported. Without external oxidants and expensive additives, this reaction features mild reaction conditions, compatibility with various functional groups, and good to excellent regioselectivity and stereoselectivity.

| S-EPMC7771326 | biostudies-literature

Stereoselective Iridium-N,P-Catalyzed Double Hydrogenation of Conjugated Enones to Saturated Alcohols.

Project description:Asymmetric hydrogenation of prochiral substrates such as ketones and olefins constitutes an important instrument for the construction of stereogenic centers, and a multitude of catalytic systems have been developed for this purpose. However, due to the different nature of the π-system, the hydrogenation of olefins and ketones is normally catalyzed by different metal complexes. Herein, a study on the effect of additives on the Ir-N,P-catalyzed hydrogenation of enones is described. The combination of benzamide and the development of a reactive catalyst unlocked a novel reactivity mode of Crabtree-type complexes toward C═O bond hydrogenation. The role of benzamide is suggested to extend the lifetime of the dihydridic iridium intermediate, which is prone to undergo irreversible trimerization, deactivating the catalyst. This unique reactivity is then coupled with C═C bond hydrogenation for the facile installation of two contiguous stereogenic centers in high yield and stereoselectivity (up to 99% ee, 99/1 d.r.) resulting in a highly stereoselective reduction of enones.

| S-EPMC9121388 | biostudies-literature

Unstabilized azomethine ylides for the stereoselective synthesis of substituted piperidines, tropanes, and azabicyclo[3.1.0] systems.

Project description:Acid treatment of densely substituted 2-silyl-1,2-dihydropyridines provides a new and convenient entry to reactive azomethine ylides that can (1) be protonated and reduced with high stereoselectivity to give piperidines, (2) participate in [3 + 2] dipolar cycloaddition to give tropanes, and (3) undergo a Nazarov-like 6-π electrocyclization that upon reduction give 2-azabicyclo[3.1.0] systems.

| S-EPMC3586708 | biostudies-literature

Convergent synthesis of piperidines by the union of conjugated alkynes with imines: a unique regioselective bond construction for heterocycle synthesis.

Project description:A two-step process is described for the union of aromatic imines, conjugated alkynes, and aldehydes that results in a stereoselective synthesis of highly substituted piperidines. This synthetic process has been made possible by defining a unique regioselective functionalization of conjugated alkynes that establishes a suitably functionalized substrate for subsequent heterocycle-forming cationic annulation. Given the flexibility of the coupling process, heterocycles can be accessed through a process that establishes up to four stereogenic centers and four fused rings.

| S-EPMC2783831 | biostudies-literature

Regio- and stereoselective access to highly substituted vinylphosphine oxides via metal-free electrophilic phosphonoiodination of alkynes.

Project description:In general, the P-centered ring-opening of quaternary phosphirenium salts (QPrS) predominantly leads to hydrophosphorylated products, while the C-centered ring-opening is primarily confined to intramolecular nucleophilic reactions, resulting in the formation of phosphorus-containing cyclization products instead of difunctionalized products generated through intermolecular nucleophilic processes. Here, through the promotion of ring-opening of three-member rings by iodine anions and the quenching of electronegative carbon atoms by iodine cations, we successfully synthesize β-functionalized vinylphosphine oxides by the P-addition of QPrS intermediates generated in situ. Multiple β-iodo-substituted vinylphosphine oxides can be obtained with exceptional regio- and stereo-selectivity by reacting secondary phosphine oxides with unactivated alkynes. In addition, a variety of β-functionalized vinylphosphine oxides converted from C-I bonds, especially the rapid construction of benzo[b]phospholes oxides, demonstrates the significance of this strategy.

| S-EPMC11199708 | biostudies-literature

Photoinduced Carboborative Ring Contraction Enables Regio- and Stereoselective Synthesis of Multiply Substituted Five-Membered Carbocycles and Heterocycles.

Project description:We report herein a photoinduced carboborative ring contraction of monounsaturated six-membered carbocycles and heterocycles. The reaction produces substituted five-membered ring systems stereoselectively and on preparative scales. The products feature multiple stereocenters, including contiguous quaternary carbons. We show that the reaction can serve as a synthetic platform for ring system alteration of natural products. The reaction can also be used in natural product synthesis. A concise total synthesis of artalbic acid has been enabled by a sequence of photoinduced carboborative ring contraction, Rauhut-Currier reaction, and nitrilase-catalyzed hydrolysis. The synthetic utility of the reaction has been further demonstrated by converting the intermediate organoboranes to alcohols, amines, and alkenes.

| S-EPMC5737778 | 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