CuI/HMPA-Catalyzed Alkylation to Tolan: A Valuable Method for Discotic Liquid Crystal Hexabenzocoronene

Abstract:

In this paper, a novel protocol of akylation to tolan using CuI/HMPA as catalyst for synthesizing alkyl-substituted hexabenzocoronene (HBC) was described. The key step in the route was the construction of tolan bearing 2 long side chains, which was completed in the first step via coupling reaction between 4, 4’-Bis (bromomethyl) tolan (1) and Grignard Reagent in a mild condition. Afterward, Co₂(CO)₈ catalyzed cyclotrimerization gave hexaphenylbenzene derivative (HPB) which could be easily separated by column chromatography and recrystalization. The planarization of HPB was carried out with FeCl₃ /MeNO₂ to afford the desired HBC with long odd-carbon alkyl chains in good overall yields.

• Periodical: Solid State Phenomena (Volumes 181-182)
• Pages: 173-176
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.181-182.173
• Online since: November 2011
• Authors: Yu Jiang, Xu Ying Liu, Rui Cheng, Wen Guang Wang, Jia Ling Pu
• Keywords: CuI/HMPA–Catalyzed Alkylation, Grignard Reagent, Hexabenzocoronene, Tolan

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