Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Does electrophilic activation of nitroalkanes in polyphosphoric acid involve formation of nitrile oxides?

ABSTRACT: The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process? This experiment demonstrates that at least in some cases this could happen, as generated nitrile oxides were successfully intercepted as adducts of [3 + 2] cycloadditions.

SUBMITTER: Aksenov AV

PROVIDER: S-EPMC9043268 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Does electrophilic activation of nitroalkanes in polyphosphoric acid involve formation of nitrile oxides?

Aksenov Alexander V AV Aksenov Nicolai A NA Kirilov Nikita K NK Skomorokhov Anton A AA Aksenov Dmitrii A DA Kurenkov Igor A IA Sorokina Elena A EA Nobi Mezvah A MA Rubin Michael M

RSC advances 20211104 57

The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process? This experiment demonstrates that at least in some cases this could happen, as generated nitrile oxides were successfully intercepted as adducts of [3 + 2] cycloadditions. ...[more]

PMID: 35492804

Similar Datasets

Electrophilic activation of nitroalkanes in efficient synthesis of 1,3,4-oxadiazoles.

Project description:A novel methodology for general and chemoselective preparation of non-symmetric 1,3,4-oxadiazoles is developed. This unusual reaction proceeds via polyphosphoric acid-assisted activation of nitroalkanes towards nucleophilic attack with acylhydrazides.

| S-EPMC9060929 | biostudies-literature

Isoxazolodihydropyridinones: 1,3-dipolar cycloaddition of nitrile oxides onto 2,4-dioxopiperidines.

Project description:Practical and efficient methods have been developed for the diversity-oriented synthesis of isoxazolodihydropyridinones via the 1,3-dipolar cycloaddition of nitrile oxides onto 2,4-dioxopiperidines. A select few of these isoxazolodihydropyridinones were further elaborated with triazoles by copper-catalyzed azide-alkyne cycloaddition reactions. A total of 70 compounds and intermediates were synthesized and analyzed for drug likeness. Sixty-four of these novel compounds were submitted to the NIH Molecular Libraries Small Molecule Repository for high-throughput biological screening.

| S-EPMC3345193 | biostudies-literature

Polyphosphoric Acid-Promoted Efficient Synthesis of Cinnamides via Aldol Condensation of Amide.

Project description:Cinnamides are common core structures that exist in a great number of pharmaceuticals and natural products. The development of efficient methods for preparing cinnamides is in great need. We report herein an efficient polyphosphoric acid (PPA)-promoted direct aldol condensation of an amide for the convenient and straightforward preparation of cinnamides. A variety of cinnamides were obtained in moderate-to-excellent yields (65-89%). This strategy features the use of equivalent amides and a short reaction time.

| S-EPMC11477491 | biostudies-literature

Catalytic Enantioselective [3 + 2] Cycloaddition of ?-Keto Ester Enolates and Nitrile Oxides.

Project description:An enantioselective [3 + 2] cycloaddition reaction between nitrile oxides and transiently generated enolates of ?-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide-generation conditions. A versatile array of nitrile oxides and ?-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield with high levels of diastereo- and enantioselectivity. Notably, the optimal reaction conditions circumvented concurrent reactions via O-imidoylation and hetero-[3 + 2] pathways.

| S-EPMC5547566 | biostudies-literature

Transition structures of diastereoselective 1,3-dipolar cycloadditions of nitrile oxides to chiral homoallylic alcohols.

Project description:Transition structures of the 1,3-dipolar cycloaddition of substituted nitrile oxides with chiral homoallylic alcohols were explored with density functional theory (B3LYP/6-311+G(d,p)+CPCM(dichloromethane)//B3LYP/6-31+G(d)). The diastereoselectivity observed in these reactions was explained. The anti product is favored in both the thermal and magnesium-mediated reactions. Selectivity is predicted to increase in the presence of magnesium, in agreement with experimental results. The energetics of the magnesium-mediated reaction are similar to those previously found for allylic alcohols. [structure: see text].

| S-EPMC2533356 | biostudies-literature

Scope and Limitations of Boron Fluorescent Complexes from Stable Nitrile Oxides in ABPP Assays.

Project description:Anthracenenitrile oxide undergoes 1,3-dipolar cycloaddition reactions with 1-substituted-4-(prop-2-yn-1-yloxy)benzene affording the expected isoxazoles in good yields and as single regioisomers. N-O Bond cleavage and boron complexation afforded the corresponding boron complexes, derivatized with either a triple bond for click-chemistry applications or an oxime group for nitrile oxide 1,3-dipolar cycloaddition. The optical properties of these compounds show potential for employment as fluorescent tags in imaging techniques. The activity-based protein profiling assays showed good reactivity for the synthesized probes even with short peptide chains (epoxomicin). Scope and limitations are discussed in the light of the obtained results.

| S-EPMC6648418 | biostudies-literature

Ultrafast Dynamics of Photochemical Nitrile Imine Formation.

Project description:The chemical reactivity of nitrile imines is of great utility in organic synthesis with applications rapidly expanding into the materials and life sciences. Yet, our understanding of the electronic and molecular structures of nitrile imines remains incomplete and the elementary mechanism of their photoinduced generation is entirely unknown. Here, femtosecond infrared spectroscopy after 266 nm-excitation of 2,5-diphenyltetrazole has been carried out to temporally resolve the formation and structural relaxation dynamics of the nascent diphenylnitrile imine in liquid solution under ambient conditions. The infrared-spectroscopic evolution is interpreted by an initial sequence of intersystem crossings within 250 fs followed by the cleavage of N2 with formation of a structurally relaxed nitrile imine on the adiabatic ground-state singlet surface within a few tens of picoseconds. The infrared spectrum supports the notion of a "floppy" nitrile imine molecule whose equilibrium character ranges from fully propargylic to fully allenic in the room temperature liquid solution.

| S-EPMC9400991 | biostudies-literature

Microwave-assisted cyclizations promoted by polyphosphoric acid esters: a general method for 1-aryl-2-iminoazacycloalkanes.

Project description:The first general procedure for the synthesis of 5 to 7-membered 1-aryl-2-iminoazacycloalkanes is presented, by microwave-assisted ring closure of ω-arylaminonitriles promoted by polyphosphoric acid (PPA) esters. 1-Aryl-2-iminopyrrolidines were easily prepared from the acyclic precursors employing a chloroformic solution of ethyl polyphosphate (PPE). The use of trimethylsilyl polyphosphate (PPSE) in solvent-free conditions allowed for the synthesis of 1-aryl-2-iminopiperidines and hitherto unreported 1-aryl-2-iminoazepanes. The cyclization reaction involves good to high yields and short reaction times, and represents a novel application of PPA esters in heterocyclic synthesis.

| S-EPMC5082496 | biostudies-literature

Synthesis of ethoxy dibenzooxaphosphorin oxides through palladium-catalyzed C(sp(2))-H activation/C-O formation.

Project description:We report an efficient Pd-catalyzed C(sp(2))-H activation/C-O bond formation for the synthesis of ethoxy dibenzooxaphosphorin oxides from 2-(aryl)arylphosphonic acid monoethyl esters under aerobic conditions.

| S-EPMC4077535 | 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

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