Premium
Electrophilic ipso ‐Substitution and Some Unique Reaction Behavior of 1,3,6‐Tri‐ tert ‐butylazulene
Author(s) -
Shoji Taku,
Ito Shunji,
Okujima Tetsuo,
Higashi Junya,
Yokoyama Ryuji,
Toyota Kozo,
Yasunami Masafumi,
Morita Noboru
Publication year - 2009
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200801078
Subject(s) - chemistry , electrophilic substitution , substitution reaction , azulene , medicinal chemistry , electrophilic aromatic substitution , tetracyanoethylene , acetic anhydride , electrophile , yield (engineering) , cycloaddition , decarbonylation , organic chemistry , materials science , metallurgy , catalysis
Electrophilic ipso ‐substitution reactions between 1,3,6‐tri‐ tert ‐butylazulene ( 2 ) and several electrophilic reagents were examined. Friedel–Crafts and Vilsmeier reactions of 2 gave the corresponding ipso ‐substitution products in moderate to excellent yields. One of the ipso ‐substitution products, 1,6‐di‐ tert ‐butyl‐3‐formylazulene ( 5 ), was converted in high yield into the synthetically more useful azulene derivative 1,6‐di‐ tert ‐butylazulene ( 1 ) by decarbonylation on treatment with pyrrole in acetic acid. Treatment of 2 with N ‐[(trifluoromethyl)sulfonyl]pyridinium trifluoromethanesulfonate (TPT) unexpectedly afforded 1‐trifluoromethylthioazulene 10 and 1(8 H )‐azulenone 11 . Compound 2 also reacted with tetracyanoethylene (TCNE) to give an excellent yield of cycloaddition product 13 , rather than the ipso ‐substitution reaction product.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom