1,1'-Disubstituted 4-pyridinyl and 5-pyrimidinyl ferrocenes were prepd. by mech. induced solid-state Suzuki coupling reactions of 1,1'-ferrocenediboronic acid. Reaction of [h5-C5H4B(OH)2]2Fe with ArBr in the presence of 10-20% of PdCl2(dppf) and KOH or KF on Al2O3 support as a base gave [h5-C5H4B(OH)2](h5-C5H4Ar)Fe (2, 3; Ar = 4-pyridinyl, 5-pyrimidinyl), (h5-C5H4Ar)2Fe (4, 5) and mixed-ligand complex (h5-C5H4Ar1)(h5-C5H4Ar2)Fe (6, Ar1 = 4-pyridinyl, Ar2 = 5-pyrimidinyl). The reaction was initiated by grinding the palladium catalyst with KF/Al2O3 or KOH/Al2O3 and adding a few drops of MeOH together with the reactants. It is shown that the solvent-free process is much faster, and more selective, than the same reaction carried out in soln. Crystal structure of 6 is reported.
Titolo: | Mechanically Induced Expeditious and Selective Preparation of Disubstituted Pyridine/Pyrimidine Ferrocenyl Complexes. |
Autore/i: | BRAGA, DARIO; D'ADDARIO, DANIELA; POLITO, MARCO; GREPIONI, FABRIZIA |
Autore/i Unibo: | |
Anno: | 2004 |
Rivista: | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/om049958j |
Abstract: | 1,1'-Disubstituted 4-pyridinyl and 5-pyrimidinyl ferrocenes were prepd. by mech. induced solid-state Suzuki coupling reactions of 1,1'-ferrocenediboronic acid. Reaction of [h5-C5H4B(OH)2]2Fe with ArBr in the presence of 10-20% of PdCl2(dppf) and KOH or KF on Al2O3 support as a base gave [h5-C5H4B(OH)2](h5-C5H4Ar)Fe (2, 3; Ar = 4-pyridinyl, 5-pyrimidinyl), (h5-C5H4Ar)2Fe (4, 5) and mixed-ligand complex (h5-C5H4Ar1)(h5-C5H4Ar2)Fe (6, Ar1 = 4-pyridinyl, Ar2 = 5-pyrimidinyl). The reaction was initiated by grinding the palladium catalyst with KF/Al2O3 or KOH/Al2O3 and adding a few drops of MeOH together with the reactants. It is shown that the solvent-free process is much faster, and more selective, than the same reaction carried out in soln. Crystal structure of 6 is reported. |
Data prodotto definitivo in UGOV: | 2005-10-03 16:06:22 |
Appare nelle tipologie: | 1.01 Articolo in rivista |