Polyphosphoric Acids As A Reagent In Organic Chemistry

Popp, Frank D.; McEwen, William E.

doi:10.1021/cr50020a004

Cited by 171 publications

(43 citation statements)

References 112 publications

(188 reference statements)

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“…The acylium ion 15 could tautomerize under the experimental conditions to give acylium ion 21 which could undergo an intramolecular acylation to give ketone 12. Such tautomerizations have been observed under similar reaction conditions (6). Evidence for the intervention of the acylium ion 15 was found by the observation that carboxylic acid 2 under the same conditions gave an identical mixture of ketones 11 and 12.…”

Section: Rearrangement Of 2-isopropylidenecyclobutanonessupporting

confidence: 54%

“…Evidence for the intervention of the acylium ion 15 was found by the observation that carboxylic acid 2 under the same conditions gave an identical mixture of ketones 11 and 12. The formation of acylium ions from the reaction of a,P-unsaturated carboxylic acids with PPA is well documented (6). The formation of 3-methyl-A2-cyclohexenone (11) in the reaction of 4 with PPA appears at first glance to be quite unusual.…”

Section: Rearrangement Of 2-isopropylidenecyclobutanonesmentioning

confidence: 99%

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Anomalous acid-catalyzed reactions of cyclobutanones

Lee‐Ruff¹,

Turro²,

Amice³

et al. 1969

Can. J. Chem.

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Section: Rearrangement Of 2-isopropylidenecyclobutanonessupporting

confidence: 54%

Section: Rearrangement Of 2-isopropylidenecyclobutanonesmentioning

confidence: 99%

Anomalous acid-catalyzed reactions of cyclobutanones

Lee‐Ruff¹,

Turro²,

Amice³

et al. 1969

Can. J. Chem.

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“…Fortunate discoveries are always based on valuable knowledge of predecessors. In our case, one important factor was simply the well‐established use of polyphosphoric acid and orthophosphoric acid in previous, truly classical cyclodehydration studies [143,144]. In fact, sometimes it can be wise to rely on long‐established knowledge and ignore more recent parts of wisdom.…”

Section: The Tribenzotriquinacene Storymentioning

confidence: 94%

From Fragmentation to Construction—from Void to Massive: Fascination with Organic Mass Spectrometry and the Synthesis of Novel Three‐Dimensional Polycyclic Aromatic Hydrocarbons

Kuck

2015

The Chemical Record

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Detailed insights gained from our research into the gas-phase chemistry of ionized and protonated diphenylalkanes and their congeners, obtained by extended synthesis of isotopically labeled model compounds and mass spectrometry, are presented and merged with those acquired during our development of a new family of polycyclic hydrocarbons, the centropolyindanes. Aside from a Personal Account that describes "two scientific lives in one", it is demonstrated, on the one hand, how our understanding of organic chemistry can help to shed light on the details of mass spectrometric fragmentation and to unravel, in a more fundamental way, the unimolecular reactivity of gaseous ions. On the other hand, it is shown how unexpected reactivity of related ions in solution, being subject to the very same fundamentals of organic chemistry, can lead to the construction of novel and, in part, unique three-dimensional polycyclic structures that may contribute to future research in material science. Two such apparently independent fields of organic chemistry may be seen as joint contributions of the art of science.

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“…Of the commonly available cyclization agents screened for the intramolecular Friedel–Crafts acylation reaction (e.g., AlCl 3 , H 2 SO 4 , p -TsOH, TiCl 4 , P 2 O 5 ), the use of inexpensive and readily available polyphosphoric acid (PPA), requiring no additional solvent, was found to be very suitable for such a reaction in terms of good yield, short reaction time and simple workup [37,41]. Upon use of PPA as the cyclization agent, we found that the cyclization reaction of 3a – h could be performed smoothly at 150 °C as shown in Scheme 3.…”

Section: Resultsmentioning

confidence: 99%

An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives

Gao¹,

Lin²,

Li³

et al. 2012

Beilstein J. Org. Chem.

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SummaryAn efficient access to the tetracyclic-fused quinoline systems, 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives 4a–l, is described, involving the intramolecular Friedel–Crafts acylation reaction of 2-(phenoxymethyl)-4-phenylquinoline-3-carboxylic acid derivatives 3a–l aided by the treatment with PPA (polyphosphoric acid) or Eaton’s reagent. The required starting compound (2) was obtained by Friedländer reaction of 2-aminobenzophenone (1) with 4-chloroethylacetoacetate by using CAN (cerium ammonium nitrate, 10 mol %) as catalyst at room temperature. The substrates 3a–l were prepared through one-pot reaction of ethyl 2-(chloromethyl)-4-phenylquinoline-3-carboxylate (2) and substituted phenols. Our developed strategy, involving a three-step route, offers easy access to tetracyclic-fused quinoline systems in short reaction times, and the products are obtained in moderate to good yields.

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Polyphosphoric Acids As A Reagent In Organic Chemistry

Cited by 171 publications

References 112 publications

Anomalous acid-catalyzed reactions of cyclobutanones

Anomalous acid-catalyzed reactions of cyclobutanones

From Fragmentation to Construction—from Void to Massive: Fascination with Organic Mass Spectrometry and the Synthesis of Novel Three‐Dimensional Polycyclic Aromatic Hydrocarbons

An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives

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