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Synthese und Kristallstruktur von ( E )‐α‐(Trifluormethyl)stilben
Author(s) -
Ruban Gerhard,
Zobel Dieter,
Koßmehl Gerhard,
Nuck Rolf
Publication year - 1980
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19801131030
Subject(s) - chemistry , steric effects , trifluoromethyl , wittig reaction , yield (engineering) , stereochemistry , medicinal chemistry , crystal structure , crystallography , organic chemistry , alkyl , materials science , metallurgy
Synthesis and X ‐Ray Structure of ( E )‐α‐(Trifluoromethyl)stilbene Starting from benzyltriphenylphosphonium chloride and ω,ω,ω‐trifluoroacetophenone α‐(trifluoromethyl)stilbene was prepared with 91% yield with a phase transfer‐catalyzed Wittig reaction with solid KF but without bases. The isolated isomer was found by X ‐ray structure analysis to have the thermodynamic preferred ( E )‐configuration. For this configuration it was determined a torsion angle of 71.3° between the two cis ‐configurated phenyl rings because of steric hindrance. AH ⃜F hydrogen bridge (distance: 223.8 pm) stabilizes the ( E )‐isomer.