ChemInform Abstract: ARYLATION AND 1‐ALKENYLATION ON THE α‐POSITION OF KETONES VIA TRIBUTYLTIN ENOLATES, CATALYZED BY A PALLADIUM COMPLEX

Kosugi, Masanori; Hagiwara, I.; Sumiya, Takashi; Migita, Toshihiko

doi:10.1002/chin.198425116

Cited by 4 publications

(4 citation statements)

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“…The intermediate pyrones also provide access to N-hydroxy-4-pyridones (8h). 17 Those precursor ketones (3e-n) not available commercially were prepared from the corresponding benzaldehydes (1) or bromides (2) by adaptation of published procedures; [18][19][20] ketone 3d, required for incorporation of the atovaquone side chain, was prepared from the commercially available acid A (Scheme 1). For the o-and m-phenoxyaryl derivatives (7o, 7p) it was found convenient to elaborate the corresponding bromophenyl pyrone intermediates (Scheme 2).…”

Section: Chemistrymentioning

confidence: 99%

Synthesis and Structure–Activity Relationships of 4-Pyridones as Potential Antimalarials

et al. 2008

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A series of diaryl ether substituted 4-pyridones have been identified as having potent antimalarial activity superior to that of chloroquine against Plasmodium falciparum in vitro and murine Plasmodium yoelii in vivo. These were derived from the anticoccidial drug clopidol through a systematic study of the effects of varying the side chain on activity. Relative to clopidol the most active compounds show >500-fold improvement in IC50 for inhibition of P. falciparum in vitro and about 100-fold improvement with respect to ED50 against P. yoelii in mice. These compounds have been shown elsewhere to act selectively by inhibition of mitochondrial electron transport at the cytochrome bc1 complex.

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Section: Chemistrymentioning

confidence: 99%

Synthesis and Structure–Activity Relationships of 4-Pyridones as Potential Antimalarials

et al. 2008

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“…The few palladium-catalyzed couplings of enolates with aryl or vinyl halides known in 1997 usually required preformed zinc 3 or tin enolates [4][5][6][7] and encompassed only acetates or methyl ketones. Success with metal-mediated coupling of enolates had been achieved initially with stoichiometric quantities of nickel complexes.…”

Section: Introductionmentioning

confidence: 99%

Palladium-Catalyzed α-Arylation of Carbonyl Compounds and Nitriles

2003

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The palladium-catalyzed alpha-arylation of ketones has become a useful and general synthetic method. In this process, an enolate is generated from a ketone and base in the presence of an aryl halide, and a palladium catalyst couples this enolate with the aryl halide. With the advent of new catalysts composed of sterically hindered, electron-rich alkylphosphine and N-heterocyclic carbene ligands, this process now encompasses a broad range of enolates and related anions, including those derived from amides, esters, aldehydes, nitriles, malonates, cyanoesters, nitroalkanes, sulfones, and lactones. In the proposed mechanism for this reaction, the carbon-carbon bond of the product is formed by reductive elimination from an arylpalladium enolate intermediate. The structures and reactions of arylpalladium complexes of enolate, cyanoalkyl, and malonate ions have been studied to determine how the binding mode and electronic and steric parameters influence the rate and mechanism of reductive elimination.

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“…The synthetic protocol for the four APB phenyl ring positional isomers consisted of a two‐step sequence starting with the respective bromobenzofuran (synthetic route shown in supplemental data) . This was cross‐coupled with iso‐propenyl acetate in the presence of palladium (II) chloride, tri(o‐tolyl)phosphine and tributyl tin methoxide to produce a ketone intermediate which was then reductively aminated with ammonium acetate and sodium cyanoborohydride to afford the amine. The yields of final products, from their respective bromobenzofuran starting materials, were found to reasonably low (around 20 %) and flash column chromatography was required for purification at each stage of the protocol.…”

Section: Resultsmentioning

confidence: 99%

Identification of (2‐aminopropyl)benzofuran (APB) phenyl ring positional isomers in Internet purchased products

Stanczuk

Morris

Gardner

et al. 2013

Drug Testing and Analysis

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5-(2-Aminopropyl)benzofuran (5-APB), a 'research chemical' that was first reported by UK authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) in 2010, is anecdotally reported to produce a combination of stimulant and entactogenic effects. More recently, in 2011, 6-(2-aminopropyl)benzofuran (6-APB) was identified by Hungarian authorities. To confirm positional isomer identity in Internet purchased products, 4- 5- 6- and 7-APBs were synthesized and found to be separable by gas chromatography (as heptafluorobutyramide derivatives) and liquid chromatography. The analyses of products purchased from online vendors of 'research chemicals' identified the presence of 5- or 6-APBs. These findings were further confirmed by liquid chromatography-mass spectrometry and (1) H nuclear magnetic resonance spectroscopy. In products containing 6-APB, the 4- positional isomer was also identified and this may have arisen during the manufacturing process.

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ChemInform Abstract: ARYLATION AND 1‐ALKENYLATION ON THE α‐POSITION OF KETONES VIA TRIBUTYLTIN ENOLATES, CATALYZED BY A PALLADIUM COMPLEX

Abstract: Die Arylbromide (I) reagieren mit dem Enolacetat (H) in Gegenwart von TributyIzinn‐methylat (Reaktionsmechunismus) zu den α‐substituienen Ketonen (III).

Cited by 4 publications

References 1 publication

Synthesis and Structure–Activity Relationships of 4-Pyridones as Potential Antimalarials

Synthesis and Structure–Activity Relationships of 4-Pyridones as Potential Antimalarials

Palladium-Catalyzed α-Arylation of Carbonyl Compounds and Nitriles

Identification of (2‐aminopropyl)benzofuran (APB) phenyl ring positional isomers in Internet purchased products

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