Radikalische Alkylierung von Chinonen: Erzeugung von Radikalen in Redoxreaktionen

Jacobsen, Niels; Torssell, Kurt

doi:10.1002/jlac.19727630115

Cited by 88 publications

(35 citation statements)

References 12 publications

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“…1. Bromides 1a-c were synthesized according to the method of direct free-radical alkylation of NQs described by Jacobsen and Torssell [10]. To this end, 2-MeNQ was reacted with x-bromoalkanoic acid, containing 5, 7 or 9 methylene groups, in the presence of ammonium persulfate and silver nitrate in the mixture of acetonitrile/water.…”

Section: Synthesis Of 2-methyl-3-(x-mercaptoalkyl)-14-naphthoquinonesmentioning

confidence: 99%

Electrochemical and structural properties of self-assembled monolayers of 2-methyl-3-(ω-mercaptoalkyl)-1,4-naphthoquinones on gold

Bulovas¹,

Dirvianskyte²,

Talaikytė³

et al. 2006

Journal of Electroanalytical Chemistry

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Section: Synthesis Of 2-methyl-3-(x-mercaptoalkyl)-14-naphthoquinonesmentioning

confidence: 99%

Electrochemical and structural properties of self-assembled monolayers of 2-methyl-3-(ω-mercaptoalkyl)-1,4-naphthoquinones on gold

Bulovas¹,

Dirvianskyte²,

Talaikytė³

et al. 2006

Journal of Electroanalytical Chemistry

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“…Bromoisoquinolines 4a-c and the substituted 2-methylnaphthoquinones 16 were synthesized according to literature procedures. 44,[46][47][48][49][50] All the other materials were purchased from commercial suppliers. (2-(1R)-menthyloxycarbonyl-1,2-dihydroisoquinoline) peroxide (11d).…”

Section: Methodsmentioning

confidence: 99%

Isoquinoline- and piperazinedione-derived α-acylamino peroxide moieties in asymmetric oxidation of sulphides and epoxidation of naphthoquinones

Blumenthal

Liebscher²

2009

Arkivoc

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The application of chiral α-acylamino hydroperoxide moieties in asymmetric sulphoxidation and epoxidations was pursued. In order to synthesize new isoquinoline-derived α-acylamino hydroperoxides isoquinolines were treated with (R)-menthyl chloroformate and hydrogen peroxide. Instead of the expected hydroperoxides novel bis(2-menthyloxycarbonyl-1,2-dihydroisoquinolin-1-yl) peroxides were obtained as 1:1 epimeric mixtures by a subsequent reaction. 1:1 mixtures of t-butyl (2-menthyloxycarbonyl-1,2-dihydroisoquinolin-1-yl) peroxides were formed from t-butyl hydroperoxide, isoquinoline and (R)-menthyl chloroformate. For eventual in situ preparation of chiral (R)-menthyloxycarbonyl-1,2-dihydroisoquinolin-1-yl) hydroperoxides and their application in stereoselective O-transfer reactions, isoquinolines were combined with (R)-menthyl chloroformate, hydrogen peroxide and metal alkoxides. These mixtures allowed a stereoselective synthesis of aryl methyl sulphoxides from corresponding sulphides. The stereoselectivity results from a kinetic resolution of racemic sulphoxides formed in the first step wherein the (S)-enantiomer was faster oxidized to the corresponding sulphone. As another type of chiral α-acylamino hydroperoxide moiety piperazinedione hydroperoxide was applied in the transformation of aryl methyl sulphides into sulphoxides. Low enantioselectivities were achieved. The same reagent allowed a high yielding epoxidation of naphthoquinones, but again in modest stereoselectivities.

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“…[102] The latter was reduced to the corresponding hydroquinone with Pd/C before being oxa-Pictet-Spengler cyclised with different aldehydes, employing 2 n HCl in Et 2 O as promoter. The resulting tricyclic hydroquinones spontaneously reoxidized to the related quinones 101 upon exposure to air.…”

Section: Syntheses Of Isochromans and Naphtho-pyrans Related To The Pmentioning

confidence: 99%

Synthesis of Oxacycles Employing the Oxa‐Pictet–Spengler Reaction: Recent Developments and New Prospects

2011

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The oxa‐Pictet–Spengler cyclization is the oxygen variation of the Pictet–Spengler reaction, in which an aromatic alcohol component (generally a β‐arylethyl alcohol) reacts with acarbonyl component (aldehyde, ketone or their masked derivatives), to yield a 1‐substituted (or 1,1′‐disubstituted)pyran fused to the aromatic ring system found in the starting alcohol. The transformation is usually promoted by Brønsted and Lewis acids. Intramolecular versions of the reaction are also known, where both components are mutually masked as an acetal. Discussed here are aspects concerning the most recent developments and new applications of this useful reaction, including the scope and limitations of new promoters, and new mechanistic pictures of this transformation. The use of novel stereochemical control strategies and the application of the reaction to the synthesis of natural products and their analogs, as well as to accessing fully synthetic bioactive compounds and new ring systems are presented, and chiral versions of the oxa‐Pictet–Spengler are also analyzed.

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Radikalische Alkylierung von Chinonen: Erzeugung von Radikalen in Redoxreaktionen

Cited by 88 publications

References 12 publications

Electrochemical and structural properties of self-assembled monolayers of 2-methyl-3-(ω-mercaptoalkyl)-1,4-naphthoquinones on gold

Electrochemical and structural properties of self-assembled monolayers of 2-methyl-3-(ω-mercaptoalkyl)-1,4-naphthoquinones on gold

Isoquinoline- and piperazinedione-derived α-acylamino peroxide moieties in asymmetric oxidation of sulphides and epoxidation of naphthoquinones

Synthesis of Oxacycles Employing the Oxa‐Pictet–Spengler Reaction: Recent Developments and New Prospects

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