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Synthesis of 1,2,3,4‐Tetramethyl‐ and 1,2,3,4‐Tetraethylfluorene through a Dewar Benzene Pathway
Author(s) -
Janková Štěpánka,
Schulz Jiří,
Hybelbauerová Simona,
Císařová Ivana,
Štěpnička Petr,
Kotora Martin
Publication year - 2013
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.201201343
Subject(s) - chemistry , thionyl chloride , benzene , hydrolysis , medicinal chemistry , chloride , benzene derivatives , catalysis , organic chemistry , chemical synthesis , biochemistry , in vitro
A simple and selective synthesis of 1,2,3,4‐tetra(m)ethylfluorenones and ‐fluorenes was achieved by using Dewar benzenes as important intermediates. The corresponding Dewar benzenes were prepared by reactions of tetraalkylcyclobutadiene–AlCl 3 complexes with methyl phenylpropynoate. Their subsequent hydrolysis followed by photochemical rearrangement provided substituted biphenylcarboxylic acids. Treatment of the prepared acids with thionyl chloride gave rise to the fluorenones, which were reduced to the respective fluorenes. A Ru complex with 1,2,3,4‐tetraethylfluorenone was prepared.