An Ion‐Pair Immobilization Strategy in Rhodium‐Catalyzed Asymmetric Transfer Hydrogenation of Aromatic Ketones
A chiral diamine‐based homogeneous cationic rhodium catalyst was developed and two heterogeneous cationic rhodium catalysts were obtained via the encapsulation of the homogeneous cationic rhodium catalyst within Me‐SBA‐15 and Me‐SBA‐16. All these catalysts presented excellent catalytic activities and high enantioselectivities in ultrasound‐promoted asymmetric transfer hydrogenation of aromatic ketones and represent a successful use of the ion‐pair immobilization strategy. More importantly, the encapsulation of the cationic rhodium functionality within Me‐SBA‐16 had an obvious high recyclability, in which the recycled catalyst could be reused nine times without significantly affecting its enantioselectivity, showing good potential in industrial application.
Document Type: Research Article
Affiliations: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, People's Republic of China, phone: (+86)-21-6432-1819, Fax: (+86)-21-6432-1819
Publication date: November 26, 2012