A. Batsanov, D. Hérault, J. Howard
Mar 30, 2007
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0
Influential Citations
23
Citations
Journal
Organometallics
Abstract
N,N‘-Diisopropylferrocenecarboxamide is utilized for an asymmetric, directed metalation approach to several planar chiral bifunctional ferrocene derivatives. Directed metalation using n-butyllithium-(−)-sparteine on N,N‘-diisopropylferrocenecarboxamide can be achieved to give high yields of the corresponding boronic acid; however, it was found that a sequence involving asymmetric directed metalation−bromination, followed by lithium−halogen exchange, was more convenient to access the same derivatives since this allowed straightforward determination of the enantiomeric excess. (pR)-2-[(N,N-Diisopropylamino)methyl]ferrocenylboronic acid and derivatives thereof could be readily accessed with high enantiomeric excess, followed by amide reduction.