Imidazolium salts incorporating functional groups represent a class of compounds having great versatility due to their wide range of applications as task specific ionic liquids (ILs)1 or N-heterocyclic carbene precursors (NHCs)2. Recently our research in this field has been dealing with the high-purity synthesis of t-butyloxylcarbonyl (Boc)-protected and deprotected amino-functionalized imidazolium cation [NHR1CH2CH2ImR2]+ ([1]+, R1 = Boc, H; R2 = Me, Bz, Allyl) and related NHC-Ag(I) silver complexes have been obtained by reacting [1]+ with Ag2O.3 Here we report the synthesis of new NHC-Rh(I) (2) complexes that contain an axis of chirality. The enantiomerical inversion has been investigated by variable-temperature NMR spectroscopy, DFT calculation and X-ray diffraction. The catalytic behaviour of 2 in the 1,2 addition reaction of aryl aldehydes with boronic acid will be also presented and discussed.
N-heterocyclic carbenes rhodium complexes: conformational analysis and catalytic studies / G. Solinas; L. Busetto; M.C. Cassani; C. Femoni; M. Mancinelli; R. Mazzoni. - STAMPA. - 1:(2010), pp. FC29-FC29. (Intervento presentato al convegno N-heterocyclic carbenes rhodium complexes: conformational analysis and catalytic studies tenutosi a Pesaro nel 18-20 Ottobre 2010).
N-heterocyclic carbenes rhodium complexes: conformational analysis and catalytic studies
SOLINAS, GAVINO;BUSETTO, LUIGI;CASSANI, MARIA CRISTINA;FEMONI, CRISTINA;MANCINELLI, MICHELE;MAZZONI, RITA
2010
Abstract
Imidazolium salts incorporating functional groups represent a class of compounds having great versatility due to their wide range of applications as task specific ionic liquids (ILs)1 or N-heterocyclic carbene precursors (NHCs)2. Recently our research in this field has been dealing with the high-purity synthesis of t-butyloxylcarbonyl (Boc)-protected and deprotected amino-functionalized imidazolium cation [NHR1CH2CH2ImR2]+ ([1]+, R1 = Boc, H; R2 = Me, Bz, Allyl) and related NHC-Ag(I) silver complexes have been obtained by reacting [1]+ with Ag2O.3 Here we report the synthesis of new NHC-Rh(I) (2) complexes that contain an axis of chirality. The enantiomerical inversion has been investigated by variable-temperature NMR spectroscopy, DFT calculation and X-ray diffraction. The catalytic behaviour of 2 in the 1,2 addition reaction of aryl aldehydes with boronic acid will be also presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
