Supported N-heterocyclic carbene rhodium complexes as highly selective hydroformylation catalysts

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2009-08, Vol.309 (1), p.131-136
• Main Authors: Gil, Wojciech, Boczoń, Katarzyna, Trzeciak, Anna M., Ziółkowski, Józef J., Garcia-Verdugo, Eduardo, Luis, Santiago V., Sans, Victor
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Hydroformylation; Immobilized catalyst; N-heterocyclic carbene; Rhodium; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2009.05.007

New rhodium(I) N-heterocyclic carbene complexes supported on polymeric monoliths applied as catalyst precursors of 1-hexene hydroformylation at 10 atm of CO/H 2 with a small amount of P(OPh) 3 as a modifying ligand, produced ca. 80% of aldehydes with n/iso ratio of ca. 6 in eight successive runs. New supported rhodium(I) catalyst precursors were obtained in reaction of [Rh(OMe)(cod)] 2 with polymeric monoliths containing methyl-imidazolium moieties and applied in 1-hexene hydroformylation at 10 atm of CO/H 2. Under solventless conditions with a small amount of P(OPh) 3 as a modifying ligand, [P(OPh) 3]/[Rh] = 2, ca. 80% of aldehydes with a high n/iso ratio of ca. 6 was obtained in eight successive runs. When P(OCH 2CF 3) 3 was used instead of P(OPh) 3, n/iso ratios up to 49.8 were obtained, however, the systems were active only in two subsequent reactions. With PPh 3 as a modifying ligand, the yield of aldehydes decreased to ca. 20% already in the third run and n/iso was ca. 3.