Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F03%3A00036035" target="_blank" >RIV/00216224:14310/03:00036035 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions

Popis výsledku v původním jazyce

Although the reactions of enol ethers of aryl methyl ketones with benzoquinone make it easy to prepare nonracemic helicenes that are substituted by hydroxyl groups at their 1,omega-positions, the hydroxyl groups fail to facilitate the introduction of electrophiles ortho to them. However, ethers of [6]- and [7]helicenols prepared in this way, seemingly because of the activation by the alkoxyl groups at the 6-positions, combine with electrophilic reagents to introduce bromines and acyl groups exactly intothese positions. Moreover, these bromine and acyl groups can be transformed into other functional groups (including phosphine oxides and acetylenes), the ether functions adjacent to these functional groups can then be removed, and the phenols can be oxidized to quinone-acetals. An alternative way to introduce functional groups next to the phenols is to rearrange their phosphate esters. Two reactions that differentiate the ends of the helicenes are also described.

Název v anglickém jazyce

Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions

Popis výsledku anglicky

Although the reactions of enol ethers of aryl methyl ketones with benzoquinone make it easy to prepare nonracemic helicenes that are substituted by hydroxyl groups at their 1,omega-positions, the hydroxyl groups fail to facilitate the introduction of electrophiles ortho to them. However, ethers of [6]- and [7]helicenols prepared in this way, seemingly because of the activation by the alkoxyl groups at the 6-positions, combine with electrophilic reagents to introduce bromines and acyl groups exactly intothese positions. Moreover, these bromine and acyl groups can be transformed into other functional groups (including phosphine oxides and acetylenes), the ether functions adjacent to these functional groups can then be removed, and the phenols can be oxidized to quinone-acetals. An alternative way to introduce functional groups next to the phenols is to rearrange their phosphate esters. Two reactions that differentiate the ends of the helicenes are also described.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CC - Organická chemie

OECD FORD obor

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Projekt

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Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2003

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Organic Chemistry

ISSN

0022-3263

e-ISSN

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Svazek periodika

2003

Číslo periodika v rámci svazku

68

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

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Kód UT WoS článku

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EID výsledku v databázi Scopus

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