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Probing the stereo‐electronic properties of cationic rhodium complexes bearing chiral diphosphine ligands by 103 Rh NMR
Author(s) -
Fabrello Amandine,
Dinoi Chiara,
Perrin Lionel,
Kalck Philippe,
Maron Laurent,
Urrutigoity Martine,
DechyCabaret Odile
Publication year - 2010
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2677
Subject(s) - diphosphines , chemistry , rhodium , binap , steric effects , cationic polymerization , carbon 13 nmr , proton nmr , catalysis , stereochemistry , enantioselective synthesis , organic chemistry
103 Rh NMR represents a powerful tool to assess the global electronic and steric contribution of diphosphine ligands on [Rh(COD)(diphosphine)] + complexes. In the case of DIOP, BINAP and MeDUPHOS, this approach proved to be more informative than classical CO‐stretching frequency measurements. After validation, this method has been extended to a set of seven diphosphines. 103 Rh NMR measurements on [Rh(COD)(diphosphine)]PF 6 lead to the following order of donor properties: dppe > MeBPE > MeDUPHOS > dppb > DIOP > BINAP > Tol‐BINAP. This trend has been validated by DFT in the case of DIOP, BINAP and MeDUPHOS. In conjunction, 31 P NMR chemical shift has been shown to reflect the ring constraints of the Rh‐diphosphine scaffold. This contribution is a step towards a mechanistic investigation of the catalytic hydrogenation of unsaturated substrates by 103 Rh NMR and DFT. Copyright © 2010 John Wiley & Sons, Ltd.