Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Alcohol-assisted phosphine catalysis: one-step syntheses of dihydropyrones from aldehydes and allenoates.

ABSTRACT: This paper describes the phosphine-catalyzed annulation of methyl allenoate with various aromatic aldehydes to form 6-aryl-4-methoxy-5,6-dihydro-2-pyrones. In this reaction, the addition of an alcohol was necessary to induce dihydropyrone formation, with the optimal agent being methanol. Moreover, the addition of n-butyllithium suppressed the formation of the noncyclized product, leading to the exclusive isolation of the dihydropyrone. This method provides an efficient, one-step route toward disubstituted dihydropyrones from simple, stable starting materials.

SUBMITTER: Creech GS

PROVIDER: S-EPMC2532593 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Alcohol-assisted phosphine catalysis: one-step syntheses of dihydropyrones from aldehydes and allenoates.

Creech Gardner S GS Kwon Ohyun O

Organic letters 20080104 3

This paper describes the phosphine-catalyzed annulation of methyl allenoate with various aromatic aldehydes to form 6-aryl-4-methoxy-5,6-dihydro-2-pyrones. In this reaction, the addition of an alcohol was necessary to induce dihydropyrone formation, with the optimal agent being methanol. Moreover, the addition of n-butyllithium suppressed the formation of the noncyclized product, leading to the exclusive isolation of the dihydropyrone. This method provides an efficient, one-step route toward dis ...[more]

PMID: 18173275

Similar Datasets

One-pot phosphine-catalyzed syntheses of quinolines.

Project description:In this study we developed an efficient one-pot procedure for the preparation of 3-substituted and 3,4-disubstituted quinolines from stable starting materials (activated acetylenes reacting with o-tosylamidobenzaldehydes and o-tosylamidophenones, respectively) under mild conditions. The reaction appears to operate under a general base catalysis mechanism, instigated by the β-phosphonium enoate α-vinyl anion generated in situ through nucleophilic addition of PPh(3) to the activated alkyne. Michael addition of the deprotonated tosylamides to the activated alkynes and subsequent rapid aldol cyclization led to the formation of labile N-tosyldihydroquinoline intermediates. Driven by aromatization, detosylation of the dihydroquinoline intermediates occurred readily in the presence of dilute aqueous HCl to give the final quinoline products.

| S-EPMC3459651 | biostudies-literature

Stereoselective Syntheses of α,β-Unsaturated γ-Amino Esters Through Phosphine-Catalyzed γ-Umpolung Additions of Sulfonamides to γ-Substituted Allenoates.

Project description:α,β-Unsaturated γ-amino esters can be synthesized efficiently and stereoselectively through phosphine-catalyzed γ-umpolung additions of sulfonamides to γ-substituted allenoates. The structures of the sulfonamide and γ-substituted allenoate partners can be varied to achieve a range of α,β-unsaturated γ-amino esters with potentially interesting chemical and biological properties.

| S-EPMC4450090 | biostudies-literature

Lewis Base-Bronsted Acid-Enzyme Catalysis in Enantioselective Multistep One-Pot Syntheses.

Project description:Establishing one-pot, multi-step protocols combining different types of catalysts is one important goal for increasing efficiency in modern organic synthesis. In particular, the high potential of biocatalysts still needs to be harvested. Based on an in-depth mechanistic investigation of a new organocatalytic protocol employing two catalysts {1,4-diazabicyclo[2.2.2]octane (DABCO); benzoic acid (BzOH)}, a sequence was established providing starting materials for enzymatic refinement (ene reductase; alcohol dehydrogenase): A gram-scale access to a variety of enantiopure key building blocks for natural product syntheses was enabled utilizing up to six catalytic steps within the same reaction vessel.

| S-EPMC8360128 | biostudies-literature

Phosphine-catalyzed divergent domino processes between γ-substituted allenoates and carbonyl-activated alkenes.

Project description:Highly enantioselective and chemodivergent domino reactions between γ-substituted allenoates and activated alkenes have been developed. In the presence of NUSIOC-Phos, triketone enone substrates smoothly reacted with γ-substituted allenoates to form bicyclic furofurans in good yields with high stereoselectivities. Alternatively, the reaction between diester-activated enone substrates and γ-substituted allenoates formed chiral conjugated 1,3-dienes in good yields with excellent enantioselectivities. Notably, by employing substrates with subtle structural difference, under virtually identical reaction conditions, we were able to access two types of chiral products, which are of biological relevance and synthetic importance.

| S-EPMC8926293 | biostudies-literature

Phosphine-catalyzed asymmetric additions of malonate esters to {gamma}-substituted allenoates and allenamides.

Project description:Because carbonyl groups are ubiquitous in organic chemistry, the ability to synthesize functionalized carbonyl compounds, particularly enantioselectively, is an important objective. We have developed a straightforward and versatile method for catalytic asymmetric carbon-carbon bond formation at the γ-position of carbonyl compounds, specifically, phosphine-catalyzed additions of malonate esters to γ-substituted allenoates and allenamides. Mechanistic studies have provided insight into the reaction pathway.

| S-EPMC2996437 | biostudies-literature

Transition from Kwon [4+2]- to [3+2]-cycloaddition enabled by AgF-assisted phosphine catalysis.

Project description:Phosphine catalysis generally relies on the potential of carbanion-phosphonium zwitterions that are generated via nucleophilic addition of phosphine catalyst to electrophilic reactants. Consequently, structural modification of zwitterions using distinct electrophilic reactants has emerged as a prominent strategy to enhance catalysis diversity. Herein, we present an alternative strategy that utilizes AgF additive to expand phosphine catalysis. We find that AgF can readily transform the canonical carbanion-phosphonium zwitterion into silver enolate-fluorophosphorane intermediate, eventually furnishing a P(III)/P(V) catalytic cycle. This strategy has been successfully applied to the phosphine-catalyzed reaction of 2-substituted allenoate and imine, resulting in the transition from Kwon [4 + 2] cycloaddition to [3 + 2] cycloaddition. This [3 + 2] cycloaddition features remarkable diastereoselectivity, high yield, and broad substrate scope. Experimental and computational studies have validated the proposed mechanism. Given the prevalence of carbanion-phosphonium zwitterions in phosphine catalysis, this AgF-assisted strategy is believed to hold significant potential for advancing P(III)/P(V) catalysis.

| S-EPMC11324788 | biostudies-literature

Phosphine Mediated Conjugation of S-Nitrosothiols and Aldehydes.

Project description:S-Nitrosothiols (SNO) and their biological implications as an important post-translational modification are under active investigation. In our work on bioorthogonal reactions of protein SNO we have uncovered chemistry of this functionality that shows synthetic promise. Herein we report a phosphine-mediated reaction between SNO and aldehydes to form thioimines. A simple synthesis of benzoisothiazole based on this reaction is presented.

| S-EPMC4467916 | biostudies-literature

Phosphine-catalyzed enantioselective [3 + 2] cycloadditions of γ-substituted allenoates with β-perfluoroalkyl enones.

Project description:The enantioselective construction of densely functionalized cyclopentene bearing contiguous three stereocenters has been a challenging task in organic synthesis. Herein, we present a phoshine-catalyzed highly regio-, diastereo- and enantioselective [3 + 2] cycloaddition of γ-substituted allenoates with β-perfluoroalkyl enones, delivering a wide range of densely functionalized perfluoroalkylated cyclopentenes with three contiguous chiral stereocenters.

| S-EPMC5590097 | biostudies-literature

HCl•DMPU-Assisted One-pot and Metal-free Conversion of Aldehydes to Nitriles.

Project description:We report an efficient HCl•DMPU assisted one-pot conversion of aldehydes into nitriles. The use of HCl•DMPU as both an acidic source as well as a non-nucleophilic base constitutes an environmentally mild alternative for the preparation of nitriles. Our protocol proceeds smoothly without the use of toxic reagents and metal catalysts. Diverse functionalized aromatic, aliphatic and allylic aldehydes incorporating various functional groups were successfully converted to nitriles in excellent to quantitative yields. This protocol is characterized by a broad substrate scope, mild reaction conditions, and high scalability.

| S-EPMC8009297 | biostudies-literature

Photo and copper dual catalysis for allene syntheses from propargylic derivatives via one-electron process.

Project description:Different from the traditional two-electron oxidative addition-transmetalation-reductive elimination coupling strategy, visible light has been successfully integrated into transition metal-catalyzed coupling reaction of propargylic alcohol derivatives highly selectively forming allenenitriles: specifically speaking, visible light-mediated Cu-catalyzed cyanation of propargylic oxalates has been realized for the general, efficient, and exclusive syntheses of di-, tri, and tetra-substituted allenenitriles bearing various synthetically versatile functional groups. A set of mechanistic studies, including fluorescence quenching experiments, cyclic voltammetric measurements, radical trapping experiments, control experiments with different photocatalyst, and DFT calculation studies have proven that the current reaction proceeds via visible light-induced redox-neutral reductive quenching radical mechanism, which is a completely different approach as compared to the traditional transition metal-catalyzed two-electron oxidative addition processes.

| S-EPMC9177964 | 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