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Highly Stereoselective Synthesis of Novel Multistereogenic Bis ‐ Bifunctional Ligands Based on [2.2]Paracyclophane‐ 4,7‐quinone, their Structure Elucidation and Application in Asymmetric Catalysis
Author(s) -
Vorontsova Natalia,
Vorontsov Evgenii,
Antonov Dmitrii,
Starikova Zoya,
Butin Kim,
Bräse Stefan,
Höfener Sebastian,
Rozenberg Valeria
Publication year - 2005
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200404200
Subject(s) - chemistry , bifunctional , enantioselective synthesis , diethylzinc , benzaldehyde , quinone , stereochemistry , cyclophane , planar chirality , stereoselectivity , catalysis , organic chemistry , crystal structure
Bis ‐ bifunctional cis ‐4,7‐diarylsubstituted‐4,7‐dihydroxy‐4,7‐dihydro[2.2]paracyclophanes 3–6 were synthesized by a highly diastereoselective reaction of ortho ‐substituted aryllithium reagents with [2.2]paracyclophane‐4,7‐quinone ( 1 ). Enantiomerically pure diols 3–5 were tested as chiral inductors in the enantioselective addition of diethylzinc to benzaldehyde (up to 93.5% ee). Acid dehydration of cis ‐4,7‐di(2‐methoxyphenyl)‐4,7‐dihydroxy‐4,7‐dihydro[2.2]paracyclophane ( 3 ) results in 4,7‐dihydro‐7,8‐di(2‐methoxyphenyl)[2.2]paracyclophane‐4‐one ( 8 ) – a planar chiral cyclohexadienone of the [2.2]paracyclophane series with a para ‐semiquinoid substructure. X‐Ray investigations of compounds 3, 4 and 8 were performed.