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.
Titolo: | N-heterocyclic carbenes rhodium complexes: conformational analysis and catalytic studies |
Autore/i: | SOLINAS, GAVINO; BUSETTO, LUIGI; CASSANI, MARIA CRISTINA; FEMONI, CRISTINA; MANCINELLI, MICHELE; MAZZONI, RITA |
Autore/i Unibo: | |
Anno: | 2010 |
Titolo del libro: | Co.G.I.C.O. 9 (9° Congresso del Gruppo Interdivisionale di Chimica Organometallica della SCI) |
Pagina iniziale: | 89 |
Pagina finale: | 89 |
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. |
Data prodotto definitivo in UGOV: | 6-dic-2010 |
Appare nelle tipologie: | 4.02 Riassunto (Abstract) |