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Comparing various chiral dirhodium tetracarboxylates in the dirhodium method
Author(s) -
Mattiza Jens T.,
Harada Nobuyuki,
Kuwahara Shunsuke,
Hassan Zahid,
Duddeck Helmut
Publication year - 2009
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20706
Subject(s) - chemistry , enantiopure drug , chirality (physics) , propionate , stereochemistry , aryl , ring (chemistry) , catalysis , enantioselective synthesis , organic chemistry , symmetry breaking , chiral symmetry breaking , physics , alkyl , quantum mechanics , nambu–jona lasinio model
Three enantiopure dirhodium tetracarboxylates are compared in their NMR properties to differentiate chiral ligands of various kinds ( dirhodium method ). The complex with four ( S )‐2‐methoxy‐2‐(1‐naphthyl) propionate (MαNP) residues ( Rh2) is slightly better for strong donors than the complex with four Mosher acid anions ( Rh1 ), but it is inferior for weak donors. On the other hand, the dirhodium tetracarboxylate complex with four ( S )‐ N ‐phthaloyl‐( S )‐ tert .‐leucinate residues ( Rh3 ) is generally more effective than Rh1 . These results are explained by the estimated conformational behavior of the substituents within the equatorial acid residues and the anisotropy (ring‐current) effect of aryl groups. Chirality 2009. © 2009 Wiley‐Liss, Inc.