Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Divergent Synthesis of Functionalized Indenopyridin-2-ones and 2-Pyridones via Benzyl Group Transfer: Two Cases of Aza-semipinacol-Type Rearrangement.

ABSTRACT: The synthesis of bromo-substituted indeno[1,2-b]pyridin-2-ones and 3-iodo-5-benzyl-substituted 2-pyridones, starting from easily available 6-benzyl-3,6-dihydropyridin-2(1H)-ones, triggered by NBS and NIS, respectively, is described. In both syntheses, a transfer of a benzyl group from the C6 to C5 lactam position occurred, indicating a novel aza-semipinacol-type rearrangement. Identification of intermediate compounds in both transformations supported the proposed reaction mechanisms. In the process of checking the scope of the method's application, functionalized indeno[1,2-b]pyridin-2-ones and 5-benzyl-2-pyridones were obtained.

SUBMITTER: Sosnicki JG

PROVIDER: S-EPMC9706813 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Divergent Synthesis of Functionalized Indenopyridin-2-ones and 2-Pyridones via Benzyl Group Transfer: Two Cases of Aza-semipinacol-Type Rearrangement.

Sośnicki Jacek G JG Borzyszkowska-Ledwig Aleksandra A Idzik Tomasz J TJ Lubowicz Magdalena M MM Maciejewska Gabriela G Struk Łukasz Ł

Organic letters 20221111 46

The synthesis of bromo-substituted indeno[1,2-<i>b</i>]pyridin-2-ones and 3-iodo-5-benzyl-substituted 2-pyridones, starting from easily available 6-benzyl-3,6-dihydropyridin-2(1<i>H</i>)-ones, triggered by NBS and NIS, respectively, is described. In both syntheses, a transfer of a benzyl group from the C6 to C5 lactam position occurred, indicating a novel aza-semipinacol-type rearrangement. Identification of intermediate compounds in both transformations supported the proposed reaction mechanism ...[more]

PMID: 36367325

Similar Datasets

Organophotoredox-catalyzed semipinacol rearrangement via radical-polar crossover.

Project description:Over the past century, significant progress in semipinacol rearrangement involving 1,2-migration of α-hydroxy carbocations has been made in the areas of catalysis and total synthesis of natural products. To access the α-hydroxy carbocation intermediate, conventional acid-mediated or electrochemical approaches have been employed. However, the photochemical semipinacol rearrangement has been underdeveloped. Herein, we report the organophotoredox-catalyzed semipinacol rearrangement via radical-polar crossover (RPC). A phenothiazine-based organophotoredox catalyst facilitates the generation of an α-hydroxy non-benzylic alkyl radical followed by oxidation to the corresponding carbocation, which can be exploited to undergo the semipinacol rearrangement. As a result, the photochemical approach enables decarboxylative semipinacol rearrangement of β-hydroxycarboxylic acid derivatives and alkylative semipinacol type rearrangement of allyl alcohols with carbon electrophiles, producing α-quaternary or α-tertiary carbonyls bearing sp3-rich scaffolds.

| S-EPMC9106707 | biostudies-literature

Organocatalytic Asymmetric Synthesis of Functionalized 1,3,5-Triarylpyrrolidin-2-ones via an Aza-Michael/Aldol Domino Reaction.

Project description:The organocatalytic asymmetric synthesis of functionalized 1,3,5-triarylpyrrolidin-2-ones bearing three contiguous stereocenters through an aza-Michael/aldol domino reaction of ?-ketoamides with ?,?-unsaturated aldehydes is described. The domino products were further derivatized by aldehyde olefination under one-pot conditions. The reaction proceeds with excellent diastereoselectivities (>20:1) and good to excellent enantioselectivities (60-96% ee).

| S-EPMC4178285 | biostudies-other

A divergent mechanistic course of Pd(0)-catalyzed aza-Claisen rearrangement and aza-Rautenstrauch-type cyclization of N-allyl ynamides.

Project description:A fascinating mechanistic study of ynamido-palladium-pi-allyl complexes is described that features isolation of a unique silyl ketenimine via aza-Claisen rearrangement, which can be accompanied by an unusual thermal N-to-C 1,3-Ts shift in the formation of tertiary nitriles and a novel cyclopentenimine formation via a palladium-catalyzed aza-Rautenstrauch-type cyclization pathway.

| S-EPMC2862050 | biostudies-literature

Carbamoyl radical-mediated synthesis and semipinacol rearrangement of β-lactam diols.

Project description:In an approach to the biologically important 6-azabicyclo[3.2.1]octane ring system, the scope of the tandem 4-exo-trig carbamoyl radical cyclization-dithiocarbamate group transfer reaction to ring-fused β-lactams is evaluated. β-Lactams fused to five-, six-, and seven-membered rings are prepared in good to excellent yield, and with moderate to complete control at the newly formed dithiocarbamate stereocentre. No cyclization is observed with an additional methyl substituent on the terminus of the double bond. Elimination of the dithiocarbamate group gives α,β- or β,γ-unsaturated lactams depending on both the methodology employed (base-mediated or thermal) and the nature of the carbocycle fused to the β-lactam. Fused β-lactam diols, obtained from catalytic OsO4-mediated dihydroxylation of α,β-unsaturated β-lactams, undergo semipinacol rearrangement via the corresponding cyclic sulfite or phosphorane to give keto-bridged bicyclic amides by exclusive N-acyl group migration. A monocyclic β-lactam diol undergoes Appel reaction at a primary alcohol in preference to semipinacol rearrangement. Preliminary investigations into the chemo- and stereoselective manipulation of the two carbonyl groups present in a representative 7,8-dioxo-6-azabicyclo[3.2.1]octane rearrangement product are also reported.

| S-EPMC4320754 | biostudies-literature

Expedient synthesis of spiro[3.3]heptan-1-ones via strain-relocating semipinacol rearrangements.

Project description:A novel approach for the formation of the highly strained spiro[3.3]heptan-1-one motif was developed through the reaction of 1-sulfonylcyclopropanols and lithiated 1-sulfonylbicyclo[1.1.0]butanes. Following initial nucleophilic addition to the cyclopropanone formed in situ, the resulting 1-bicyclobutylcyclopropanol intermediate is prone to a 'strain-relocating' semipinacol rearrangement in the presence of acid, directly affording the substituted spiro[3.3]heptan-1-one. The process is shown to be fully regio- and stereospecific when starting from a substituted cyclopropanone equivalent, leading to optically active 3-substituted spiro[3.3]heptan-1-ones. The reaction likely proceeds via initial protonation of the bicyclobutyl moiety followed by [1,2]-rearrangement of the resulting cyclopropylcarbinyl cation.

| S-EPMC10019042 | biostudies-literature

Photoinduced radical tandem annulation of 1,7-diynes: an approach for divergent assembly of functionalized quinolin-2(1H)-ones.

Project description:The first photocatalytic trichloromethyl radical-triggered annulative reactions of amide-linked 1,7-diynes with polyhalomethanes were established for the flexible assembly of functionalized quinolin-2(1H)-ones with generally acceptable yields. With the installation of the aryl group (R1) into the alkynyl moiety, C-center radical-initiated Kharasch-type addition/nucleophilic substitution/elimination cascade to produce quinolin-2(1H)-ones-incorporating gem-dihaloalkene, whereas three examples of polyhalogenated quinolin-2(1H)-ones were afforded when amide-linked 1,7-diynes bearing two terminal alkyne units were subjected to BrCX3 by exploiting dry acetonitrile as a solvent.

| S-EPMC11002210 | biostudies-literature

Chiral sulfide and achiral sulfonic acid cocatalyzed enantioselective electrophilic tandem selenylation semipinacol rearrangement of allenols.

Project description:A highly enantioselective electrophilic selenylation/semipinacol rearrangement of allenols has been developed, which is enabled by the cooperative catalysis of a chiral sulfide and an achiral sulfonic acid. The designed and synthesized chiral sulfide catalyst and selenylating reagent play a crucial role in enhancing both enantioselectivity and reactivity. This approach exhibits excellent regio-, chemo-, and enantioselectivity, providing access to diverse enantioenriched cyclopentanones featuring an arylselenovinyl-substituted quaternary carbon stereocenter. Furthermore, these products can be transformed into synthetically valuable alkyne, vinyl bromide, and aniline derivatives. Mechanistic studies reveal that the combination of a chiral sulfide and an achiral sulfonic acid not only facilitates the formation of catalytically active species, but also governs the enantioselectivity of the reaction. Meanwhile, density functional theory calculations disclose that four hydrogen bond interactions and a π‧‧‧π interaction are responsible for the observed enantioselectivity.

| S-EPMC11876436 | biostudies-literature

Divergent, Strain-Release Reactions of Azabicyclo[1.1.0]butyl Carbinols: Semipinacol or Spiroepoxy Azetidine Formation.

Project description:The azetidine moiety is a privileged motif in medicinal chemistry and new methods that access them efficiently are highly sought after. Towards this goal, we have found that azabicyclo[1.1.0]butyl carbinols, readily obtained from the highly strained azabicyclo[1.1.0]butane (ABB), can undergo divergent strain-release reactions upon N-activation. Treatment with trifluoroacetic anhydride or triflic anhydride triggered a semipinacol rearrangement to give keto 1,3,3-substituted azetidines. More than 20 examples were explored, enabling us to evaluate selectivity and the migratory aptitude of different groups. Alternatively, treatment of the same alcohols with benzyl chloroformate in the presence of NaI led to iodohydrin intermediates which gave spiroepoxy azetidines upon treatment with base. The electronic nature of the activating agent dictates which pathway operates.

| S-EPMC8247891 | biostudies-literature

Efficient and divergent synthesis of polyfunctionalized 2-pyridones from β-keto amides.

Project description:Efficient and divergent one-pot synthesis of polyfunctionalized 2-pyridones from β-keto amides based on reaction condition selection was developed. The methodology offers several significant advantages including mild conditions, ease of handling, high yields, and a relatively broad range of substrates. Based on various experiments and observations, a plausible mechanism for the selective synthesis of 2-pyridones was proposed.

| S-EPMC9086556 | biostudies-literature

Enantioselective PCCP Bronsted acid-catalyzed aza-Piancatelli rearrangement.

Project description:An enantioselective aza-Piancatelli rearrangement has been developed using a chiral Brønsted acid based on pentacarboxycyclopentadiene (PCCP). This reaction provides rapid access to valuable chiral 4-amino-2-cyclopentenone building blocks from readily available starting material and is operationally simple.

| S-EPMC6633596 | 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