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New Pathway to C 2 ‐Symmetric Atropoisomeric Bipyridine N , N′ ‐Dioxides and Solvent Effect in Enantioselective Allylation of Aldehydes
Author(s) -
Hrdina Radim,
Dračínský Martin,
Valterová Irena,
Hodačová Jana,
Císařová Ivana,
Kotora Martin
Publication year - 2008
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.200800141
Subject(s) - chemistry , enantioselective synthesis , chlorobenzene , acetonitrile , catalysis , solvent , silane , enantiomer , bipyridine , medicinal chemistry , 2,2' bipyridine , organic chemistry , crystal structure
The [2+2+2] cyclotrimerization of 1,7,9,15‐hexadecatetrayne with nitriles catalyzed by dicarbonylcyclopentadienylcobalt(I) opened a new pathway for the synthesis of C 2 ‐symmetrical bis(tetrahydroisoquinolines) that were used as starting material for the preparation of axially chiral bipyridine N , N′ ‐dioxides. The N , N′ ‐dioxides (1 mol%) were found to be highly catalytically active and enantioselective (up to 83% ee ) for the asymmetric allylation of aldehydes with allyl(trichloro)silane in various solvents. In addition, a dramatic solvent effect was observed where the use of different solvents induced opposite chiralities of the product with the same enantiomer of the catalyst, e.g., 65% ee ( S ) in acetonitrile (MeCN) vs. 82% ee ( R ) in chlorobenzene.