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tele Nucleophilic Substitutions of Hydrogen in m ‐(Trichloromethyl)nitrobenzenes with Cyano and Ester Carbanions
Author(s) -
Surowiec Marek,
Belekos Dimitris,
Mąkosza Mieczysław,
Varvounis George
Publication year - 2010
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.200901303
Subject(s) - chemistry , carbanion , adduct , nitrobenzene , medicinal chemistry , nucleophile , aromatization , hydrogen chloride , yield (engineering) , photochemistry , organic chemistry , catalysis , materials science , metallurgy
Stabilized carbanions of malonates, 2‐phenylacetonitrile, or isopropyl 2‐phenylacetate add to m ‐(trichloromethyl)nitrobenzene derivatives to form σ H adducts that lose a chloride ion to give intermediate exo ‐dichloromethylene nitrocyclohexadienes. These undergo re‐aromatization through 1,5‐hydrogen shift to yield tele substitution mono adducts. Depending on the stoichiometry of the nitroarene to the carbanion, further addition of the nucleophile to the tele mono adduct can yield a mixture of products that are either double or triple adducts. At low temperature, the σ H adducts undergo direct 1,2‐addition in competition with chloride ion elimination/1,5‐hydrogen shift.