Browse
Submit Data
Databases
API
Help

Dataset Information

26 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric Redox-Annulation of Cyclic Amines.

ABSTRACT: Cyclic amines such as 1,2,3,4-tetrahydroisoquinoline undergo regiodivergent annulation reactions with 4-nitrobutyraldehydes. These redox-neutral transformations enable the asymmetric synthesis of highly substituted polycyclic ring systems in just two steps from commercial materials. The utility of this process is illustrated in a rapid synthesis of (-)-protoemetinol. Computational studies provide mechanistic insights and implicate the elimination of acetic acid from an ammonium nitronate intermediate as the rate-determining step.

SUBMITTER: Kang Y

PROVIDER: S-EPMC4599696 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric Redox-Annulation of Cyclic Amines.

Kang YoungKu Y Chen Weijie W Breugst Martin M Seidel Daniel D

The Journal of organic chemistry 20151001 19

Cyclic amines such as 1,2,3,4-tetrahydroisoquinoline undergo regiodivergent annulation reactions with 4-nitrobutyraldehydes. These redox-neutral transformations enable the asymmetric synthesis of highly substituted polycyclic ring systems in just two steps from commercial materials. The utility of this process is illustrated in a rapid synthesis of (-)-protoemetinol. Computational studies provide mechanistic insights and implicate the elimination of acetic acid from an ammonium nitronate interme ...[more]

PMID: 26348653

Similar Datasets

Redox-Annulation of Cyclic Amines and ?-Ketoaldehydes.

Project description:Benzo[a]quinolizine-2-one derivatives are readily assembled from 1,2,3,4-tetrahydroisoquinoline and ?-ketoaldehydes by means of a new intramolecular redox-Mannich process. These reactions are promoted by simple acetic acid and are thought to involve azomethine ylides as reactive intermediates.

| S-EPMC4782176 | biostudies-literature

Redox-neutral α,β-difunctionalization of cyclic amines.

Project description:In contrast to the continuously growing number of methods that allow for the efficient α-functionalization of amines, few strategies exist that enable the direct functionalization of amines in the β-position. A general redox-neutral strategy is outlined for amine β-functionalization and α,β-difunctionalization that utilizes enamines generated in situ. This concept is demonstrated in the context of preparing polycyclic N,O-acetals from simple 1-(aminomethyl)-β-naphthols and 2-(aminomethyl)-phenols.

| S-EPMC4068263 | biostudies-literature

Redox-Annulations of Cyclic Amines with 2-(2-Oxoethyl)malonates.

Project description:Amines such as 1,2,3,4-tetrahydroisoquinoline undergo redox-neutral annulations with 2-(2-oxoethyl)malonates in the presence of catalytic amounts of benzoic acid. These reactions install a fully saturated five-membered ring and provide access to structures closely related to the natural products crispine A and harmicine.

| S-EPMC6060407 | biostudies-literature

Redox-Annulations of Cyclic Amines with <i>ortho</i>-Cyanomethylbenzaldehydes.

Project description:Amines such as 1,2,3,4-tetrahydroisoquinoline undergo redox-neutral annulations with ortho-cyanomethylbenzaldehydes. These amine α-C-H bond functionalization reactions are promoted by acetic acid. The resulting β-aminonitriles can be converted to the corresponding β-aminoalcohols in diastereoselective fashion.

| S-EPMC7104785 | biostudies-literature

Copper-catalysed asymmetric annulation of yne-allylic esters with amines to access axially chiral arylpyrroles.

Project description:The construction of atropisomers with 1,2-diaxes, while maintaining high enantiocontrol, presents a significant challenge due to the dynamic nature of steric hindrance at ortho-aryl substituents. Although various catalytic asymmetric methods have been developed for accessing axially chiral arylpyrroles, the synthesis of axially chiral arylpyrroles with 1,2-diaxes in a catalytic asymmetric manner has remained rare. Herein, the authors report the synthesis of diverse axially chiral arylpyrroles with 1,2-diaxes, and C-C and C-N axes through copper-catalysed asymmetirc [4 + 1] annulation of yne-allylic esters with arylamines via a remote stereocontrol strategy. This approach provides facile access to a broad range of heterobiaryl atropisomers (67 examples) in excellent enantioselectivities, each bearing one or two C-C/C-N axes, demonstrating its versatility and efficiency. The utility of this methodology is further highlighted by the transformation of the product into chiral phosphine ligand, and chiral thioureas for the use in asymmetric catalysis.

| S-EPMC11316830 | biostudies-literature

C-H functionalization of cyclic amines: redox-annulations with α,β-unsaturated carbonyl compounds.

Project description:Cyclic amines such as pyrrolidine and 1,2,3,4-tetrahydroisoquinoline undergo redox-annulations with α,β-unsaturated aldehydes and ketones. Carboxylic acid promoted generation of a conjugated azomethine ylide is followed by 6π-electrocylization, and, in some cases, tautomerization. The resulting ring-fused pyrrolines are readily oxidized to the corresponding pyrroles or reduced to pyrrolidines.

| S-EPMC4477284 | biostudies-literature

How cinchona alkaloid-derived primary amines control asymmetric electrophilic fluorination of cyclic ketones.

Project description:The origin of selectivity in the ?-fluorination of cyclic ketones catalyzed by cinchona alkaloid-derived primary amines is determined with density functional calculations. The chair preference of a seven-membered ring at the fluorine transfer transition state is key in determining the sense and level of enantiofacial selectivity.

| S-EPMC4105079 | biostudies-other

Deconstructive diversification of cyclic amines.

Project description:Deconstructive functionalization involves carbon-carbon (C-C) bond cleavage followed by bond construction on one or more of the constituent carbons. For example, ozonolysis1 and olefin metathesis2,3 have allowed each carbon in C=C double bonds to be viewed as a functional group. Despite the substantial advances in deconstructive functionalization involving the scission of C=C double bonds, there are very few methods that achieve C(sp3)-C(sp3) single-bond cleavage and functionalization, especially in relatively unstrained cyclic systems. Here we report a deconstructive strategy to transform saturated nitrogen heterocycles such as piperidines and pyrrolidines, which are important moieties in bioactive molecules, into halogen-containing acyclic amine derivatives through sequential C(sp3)-N and C(sp3)-C(sp3) single-bond cleavage followed by C(sp3)-halogen bond formation. The resulting acyclic haloamines are versatile intermediates that can be transformed into various structural motifs through substitution reactions. In this way we achieve the skeletal remodelling of cyclic amines, an example of scaffold hopping. We demonstrate this deconstructive strategy by the late-stage diversification of proline-containing peptides.

| S-EPMC6317721 | biostudies-literature

Synthesis of Polycyclic Imidazolidinones via Amine Redox-Annulation.

Project description:α-Ketoamides undergo redox-annulations with cyclic secondary amines, such as 1,2,3,4-tetrahydroisoquinoline, pyrrolidine, piperidine, and morpholine. Catalytic amounts of benzoic acid significantly accelerate these transformations. This approach provides polycyclic imidazolidinone derivatives in typically good yields.

| S-EPMC5715285 | biostudies-literature

Redox-Neutral Aromatization of Cyclic Amines: Mechanistic Insights and Harnessing of Reactive Intermediates for Amine ?- and ?-C-H Functionalization.

Project description:Cyclic amines such as pyrrolidine and piperidine are known to undergo condensations with aldehydes to furnish pyrrole and pyridine derivatives, respectively. A combined experimental and computational study provides detailed insights into the mechanism of pyrrole formation. A number of reactive intermediates (e.g., azomethine ylides, conjugated azomethine ylides, enamines) were intercepted, outlining strategies for circumventing aromatization as a valuable pathway for amine C-H functionalization.

| S-EPMC5193247 | 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