Selective bromination of perylene diimides under mild conditions

Paramasivan Rajasingh, Revital Cohen, Elijah Shirman, Linda J.W. Shimon, Boris Rybtchinski

Research output: Contribution to journalArticle

148 Citations (Scopus)

Abstract

(Chemical Equation Presented) A novel method for the bromination of perylene diimides, PDI (1), under mild conditions is reported. Variation of the reaction conditions allows mono- and dibromination of PDIs to afford 2 and 3 (these can be separated through standard procedures) or exclusive dibromination to afford 3. Pure 1,7 regioisomers are obtained through repetitive crystallization. The structure of 1,7-3b was elucidated by a single-crystal X-ray analysis. The facility of the bromination reaction, which decreases in the order 1a > 1b > 1c, depends on PDI aggregation propensities. Monobrominated PDIs were utilized for the syntheses of novel unsymmetrical piperidinyl (4a and 4b) and trimethylsilylethynyl derivatives (5a and 5b). Computational studies (DFT) on imide substituent rotation in PDIs reveal that in the case of bulky groups there is a restricted rotation leading to isomers, in agreement with our experimental results. An aromatic core twist in PDIs bearing one and two bromine substituents was also investigated by DFT.

Original languageEnglish
Pages (from-to)5973-5979
Number of pages7
JournalJournal of Organic Chemistry
Volume72
Issue number16
DOIs
Publication statusPublished - Aug 1 2007

    Fingerprint

ASJC Scopus subject areas

  • Organic Chemistry

Cite this