Abstract
The synthesis and characterization by X-ray crystallography of the complexes [Ir(cod)-(py)(L)]PF6 (L = IMes, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (2); L = IPr, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (3); L = ICy, 1,3-bis(cyclohexyl)imidazol-2-ylidene (4)) are reported. Complexes 2-4 have been employed as catalysts for transfer hydrogenation reactions from 2-propanol to a number of unsaturated substrates and their activity compared with that of the related cationic iridium(I) species [Ir(cod)(py)(SIMes)]-PF6 (1), [Ir(cod)(py)(PCy3)]PF6 (5), and complexes formed in situ from [Ir(cod)(py)(2)]PF6 and diazabutadienes (RN=CHCH=NR, DAB-R; R = cyclohexyl, DAB-Cy; R = 2,4,6-trimethylphenyl, DAB-Mes; R = adamantyl, DAB-Ad; R = 2,4,6-trimethoxyphenyl, DAB-trimethoxyphenyl). All complexes tested were found to be active catalysts for transfer hydrogenation of ketones, with complex 4 displaying the highest activity. Complex 4 also exhibits moderate activity toward simple olefins and an aromatic nitro compound.
| Original language | English |
|---|---|
| Pages (from-to) | 4246-4252 |
| Number of pages | 7 |
| Journal | Organometallics |
| Volume | 20 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 1 Oct 2001 |
Keywords
- ASYMMETRIC TRANSFER HYDROGENATION
- ASTERISK = ETA(5)-C5ME5
- ALPHA,BETA-UNSATURATED KETONES
- TRANSFER REDUCTIONS
- CARBONYL-COMPOUNDS
- STABLE CARBENES
- METAL-COMPLEXES
- AMINODIPHOSPHINE LIGANDS
- ALKANE DEHYDROGENATION
- POLYDENTATE LIGANDS