Palladium‐Catalyzed Isomerization and Hydroformylation of Olefins

Abstract

A novel selective palladium catalyst system based on bidentate 2,2'-heteroarylarylphosphines and p-TsOH has been developed for hydroformylation reactions (see scheme). By applying optimal conditions good to excellent regioselectivity is obtained for the hydroformylation of aliphatic and aromatic olefins. It is shown that a low acid concentration is crucial for obtaining high degrees of the linear isomer.The palladium-catalyzed hydroformylation of 1-octene has been studied in the presence of different phosphines and acid cocatalysts. The best results are achieved in the presence of in situ-generated palladium complexes with bidentate phosphines. It is demonstrated that the acid concentration is a crucial factor for obtaining high linear selectivity. A novel optimized catalyst based on an arylheteroarylphosphine has been applied for hydroformylation of different aliphatic and aromatic olefins. Good activity and excellent selectivity towards the linear aldehydes is achieved.

Phosphine‐ and Hydrogen‐Free: Highly Regioselective Ruthenium‐Catalyzed Hydroaminomethylation of Olefins

“…To promote the formation of the more reactive terminal olefin by isomerization, we decided to use 2-(dicyclohexylphosphino)-1-phenyl-1H-pyrrole as a ligand, which is known to promote isomerization reactions. [20] Unfortunately, this attempt did not result in a higher yield of the amine; instead larger amounts of internal olefins were detected. In accordance with these results, cyclic olefins like cyclohexene gave a low yield of the amine product (entry 3).…”

A General and Efficient Iridium‐Catalyzed Hydroformylation of Olefins

“…Owing to our interest in biphasic hydroformylation reactions, [8] we were recently attracted to the study of less common hydroformylation catalysts. [9] Herein, we present a general and efficient iridiumcatalyzed hydroformylation reaction of olefins that proceeds under mild conditions. Notably, competing hydrogenation side reactions can be suppressed.Despite industrial applications, such as the Cativa process for the synthesis of acetic acid from methanol, [10] and economical advantages over rhodium, iridium catalysts have remained undeveloped in carbonylation reactions.…”

Alternative Metalle für die homogen katalysierte Hydroformylierung

“…Hoch n-selektive Pd-katalysierte Hydroformylierung von N-Vinylphthalimid (71). [85] Schema 31. SnCl 2 als Ligand oder Lewis-Säure.…”