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

PARUCH, Kamil, Libor VYKLICKÝ, David WANG, Thomas KATZ, Christopher INCARVITO, Lev ZAKHAROV and Arnold RHEINGOLD. Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions. Journal of Organic Chemistry. 2003, vol. 2003, No 68, p. 8539-8544. ISSN 0022-3263.

Basic information

• Original name: Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions
• Name in Czech: Functionalizations of [6]- and [7]helicenes at their most sterically hindered positions
• Authors: PARUCH, Kamil (203 Czech Republic, guarantor), Libor VYKLICKÝ (203 Czech Republic), David WANG (156 China), Thomas KATZ (840 United States of America), Christopher INCARVITO (840 United States of America), Lev ZAKHAROV (840 United States of America) and Arnold RHEINGOLD (840 United States of America).
• Edition: Journal of Organic Chemistry, 2003, 0022-3263.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10401 Organic chemistry
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• Impact factor: Impact factor: 3.297
• RIV identification code: RIV/00216224:14310/03:00036035
• Organization unit: Faculty of Science
• Keywords (in Czech): helicene; functionalization; sterically hindered
• Keywords in English: helicene; functionalization; sterically hindered
• Tags: functionalization, helicene, sterically hindered

Abstract

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 into these 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.

Abstract (in Czech)

viz Anotace