Nucleophilic Reactivities of Azulene and Fulvenes

✍ Scribed by Mariusz Kędziorek; Peter Mayer; Herbert Mayr

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 157 KB
• Volume: 2009
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200801099

✦ Synopsis

Abstract

The kinetics of the reactions of azulene (1), 6,6‐dimethylfulvene (2), 6‐[4‐(dimethylamino)phenyl]fulvene (3) and 6‐(julolidin‐9‐yl)fulvene (4) with a set of benzhydrylium ions (reference electrophiles) have been investigated in MeCN. The second‐order rate constants for these reactions correlate linearly with the electrophilicity parameters (E) of the benzhydrylium ions. According to the linear free‐enthalpy relationship log k~2~(20 °C) = s(N + E), the nucleophilicity parameters N and s of the π‐nucleophiles 1–4 were determined and compared with those of other types of nucleophiles. Azulene (1, N = 6.66) is about 10 times more nucleophilic than N‐methylpyrrole and comparable to 2‐methylindole. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)