Browse
Submit Data
Databases
API
Help

Dataset Information

12 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Stereoselective Dynamic Cyclization of Allylic Azides: Synthesis of Tetralins, Chromanes, and Tetrahydroquinolines.

ABSTRACT: This report describes the stereoselective synthesis of 3-azido-tetralins, -chromanes, and -tetrahydroquinolines via a tandem allylic azide rearrangement/Friedel-Crafts alkylation. Exposure of allylic azides with a pendant trichloroacetimidate to catalytic quantities of AgSbF6 proved optimal for this transformation. This cascade successfully differentiates the equilibrating azide isomers, providing products in excellent yield and selectivity (>25 examples, up to 94% yield and >25:1 dr). In many cases, the reactive isomer is only a trace fraction of the equilibrium mixture, keenly illustrating the dynamic nature of these systems. We demonstrate the utility of this process via a synthesis of hasubanan.

SUBMITTER: Porter MR

PROVIDER: S-EPMC5989720 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Stereoselective Dynamic Cyclization of Allylic Azides: Synthesis of Tetralins, Chromanes, and Tetrahydroquinolines.

Porter Matthew R MR Shaker Rami M RM Calcanas Cristian C Topczewski Joseph J JJ

Journal of the American Chemical Society 20180110 4

This report describes the stereoselective synthesis of 3-azido-tetralins, -chromanes, and -tetrahydroquinolines via a tandem allylic azide rearrangement/Friedel-Crafts alkylation. Exposure of allylic azides with a pendant trichloroacetimidate to catalytic quantities of AgSbF<sub>6</sub> proved optimal for this transformation. This cascade successfully differentiates the equilibrating azide isomers, providing products in excellent yield and selectivity (>25 examples, up to 94% yield and >25:1 dr) ...[more]

PMID: 29303567

Similar Datasets

Stereoselective Synthesis of Fused Vinylcyclopropanes by Intramolecular Tsuji-Trost Cascade Cyclization.

Project description:A stereoselective intramolecular Tsuji-Trost cascade cyclization of (homo)allylic vicinal diacetates with a pendant ?-ketoamide or related carbon nucleophile to give ?-lactam-fused vinylcyclopropanes is reported. In addition to two new rings, the products contain three new C-C stereocenters (two of which are quaternary) with a 9:1 dr. Moreover, the reaction proceeds in >94% enantiospecificity with optically enriched starting materials, using an inexpensive carbohydrate as the source of chirality.

| S-EPMC6218879 | biostudies-literature

Stereoselective Synthesis of Substituted Oxocene Cores by Lewis Acid Promoted Cyclization.

Project description:Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of ?-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)2-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF3·OEt2 provided eight-membered cyclic ethers (oxocenes), selectively. This methodology provides convenient access to a variety of 2,4,8-trisubstituted oxocenes in good yields and excellent diastereoselectivities.

| S-EPMC5317094 | biostudies-literature

Regio- and stereoselective monoepoxidation of dienes using methyltrioxorhenium: synthesis of allylic epoxides.

Project description:Methyltrioxorhenium (MTO) complexed with pyridine was shown to be a highly effective catalyst for the regioselective monoepoxidation of conjugated di- and trienes using 30% H2O2 at or below room temperature. The resultant allylic epoxides, and the triols derived from them, are versatile synthetic intermediates as well as substructures present in many bioactive natural products. The site of epoxidation was dependent upon olefin substitution, olefin geometry (Z vs E), and the presence of electron-withdrawing substituents on adjacent carbons. For 1-acyl(silyl)oxypenta-2,4-dienes, epoxidation of the distal olefin was generally favored in contrast to the adjacent regioselectivity characteristic of Sharpless, peracid, and other directed epoxidations of hydroxylated dienes.

| S-EPMC4227570 | biostudies-literature

Gold redox catalysis for cyclization/arylation of allylic oximes: synthesis of isoxazoline derivatives.

Project description:Base-assisted diazonium activation has been employed to promote gold(i)/(iii) redox catalysis toward allylic oxime cyclization/aryl coupling. Functional isoxazolines were prepared with good to excellent yields, while the alternative photoactivation method provided trace amounts of the isoxazoline products. This study further broadens the scope of gold redox chemistry.

| S-EPMC6641983 | biostudies-literature

Cyclization cascade of allenyl azides: a dual mechanism.

Project description:A density functional theory based computational approach to describing the mechanistic course of the allene azide cycloaddition cascade sequence has been developed. The results of these calculations permit characterization of key reactive intermediates (diradicals and/or indolidenes) and explain the different behaviors observed in the experimental studies between conjugated and nonconjugated species. Furthermore, computational analysis of certain intermediates offer insight into issues of regioselectivity and stereoselectivity in cases where different reaction channels are in competition, suggesting suitable substitutions to achieve a single regioisomer in the indole synthesis via azide-allene cyclization.

| S-EPMC2527537 | biostudies-literature

Catalytic Alkene Cyclization Reactions for the Stereoselective Synthesis of Complex "Terpenoid-like" Heterocycles.

Project description:A new catalytic synthesis of densely-substituted tetrahydroquinolines is described. This reaction forms up to two rings, three bonds, and three stereogenic centers with excellent stereo- and regiocontrol in a single step. Although control experiments demonstrate that the active catalyst is protic acid, Sc(OTf)3 serves as an effective and practical pre-catalyst. The scope of this reaction is demonstrated with 21 monocyclizations and 14 bicyclization reactions.

| S-EPMC3614375 | biostudies-literature

Modular Synthesis of 1,2-Diamine Derivatives via Palladium-Catalyzed Aerobic Oxidative Cyclization of Allylic Sulfamides.

Project description:Allylic sulfamides undergo efficient aerobic oxidative cyclization at room temperature, mediated by a new Pd catalyst system consisting of 5% Pd(TFA)(2)/10% DMSO in THF. The synthetic utility of these reactions is enhanced by several features: (1) the sulfamide substrates are accessible in multi-gram scale from the corresponding allylic and primary amines, (2) the cyclic sulfamide products are readily converted to the corresponding 1,2-diamines upon treatment with LiAlH(4), and (3) substrates derived from chiral allylic amines cyclize with very high levels of diastereoselectivity.

| S-EPMC2996102 | biostudies-literature

Stereoselective Synthesis of Tertiary Allylic Amines by Titanium-Catalyzed Hydroaminoalkylation of Alkynes with Tertiary Amines.

Project description:Intermolecular hydroaminoalkylation reactions of symmetrical and unsymmetrical alkynes with tertiary amines take place in the presence of catalytic amounts of TiBn4 , Ph3 C[B(C6 F5 )4 ], and a sterically demanding aminopyridinato ligand precursor. The resulting products, synthetically and pharmaceutically useful tertiary β,γ-disubstituted allylic amines, are formed in convincing yields and with excellent stereoselectivity. Particularly promising for future applications is the fact that even the industrial side product trimethylamine can be used as a substrate.

| S-EPMC9303398 | biostudies-literature

Stereoselective cross-coupling between allylic alcohols and aldimines.

Project description:A cross-coupling reaction between an allylic alcohol and an imine is described for stereoselective allylation of aromatic and aliphatic imines. This method provides operationally simple, enantioselective access to functionalized homoallylic amines. Particularly noteworthy is direct use of a functionalized allylic alcohol as an allylating reagent without prederivatization, which obviates the use of preformed organometallic reagents or activated imine derivatives.

| S-EPMC2720054 | biostudies-literature

Stereoselective Allylic Alkylations of Amino Ketones and Their Application in the Synthesis of Highly Functionalized Piperidines.

Project description:Chelated ketone enolates are excellent nucleophiles for allylic alkylations. Electron-withdrawing groups on the allyl moiety allow subsequent intramolecular Michael additions giving rise to piperidines with up to five stereogenic centers.

| S-EPMC7079034 | 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