Highly active iridium catalysts for the hydrogenation of ketones and aldehydes.
The pressure hydrogenation capabilities of the iridium pincer complexes IrH2Cl[((i)Pr2PC2H4)2NH] (1) and IrH3[((i)Pr2PC2H4)2NH] (2) are described and compared to related results obtained previously in transfer hydrogenation. Complex 1 was shown to act as a convenient air-stable entry point to the active catalyst 2, in the presence of base and hydrogen gas. The catalysts are active in a range of solvents, including CH2Cl2 and CHCl3, in contrast to related ruthenium systems. This class of iridium complexes is very effective for the direct hydrogenation of a wide range of carbonyl compounds including ketones, diketones, alpha,beta-unsaturated ketones and aldehydes. A catalytic cycle is proposed for this system which involves an ionic heterolytic bifunctional hydrogenation mechanism.
Chen
Xuanhua
X
Kanata Chemical Technologies Inc., 101 College Street, Office 230, MaRS Centre, South Tower, Toronto, ON M5G 1L7, Canada.
Jia
Wenli
W
Guo
Rongwei
R
Graham
Todd W
TW
Gullons
Meredith A
MA
Abdur-Rashid
Kamaluddin
K
D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*
D000447:Aldehydes; D007659:Ketones; D007495:Iridium; D006859:Hydrogen