2002-92-8Relevant articles and documents
Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 14365 - 14373 (2019/09/06)
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
Regioselective Hydroesterification and Hydrocarboxylation of 3,3,3-Trifluoropropene and Pentafluorostyrene Catalyzed by Phosphine-Palladium Complex
Fuchikami, Takamasa,Ohishi, Katsuyuki,Ojima, Iwao
, p. 3803 - 3807 (2007/10/02)
The hydroesterification and hydrocarboxylation of 3,3,3-trifluoropropene (TFP) and pentafluorostyrene (PFS) catalyzed by phosphine-palladium complexes were studied.It was found that the efficiency and the product distribution of the reaction depended markedly on the nature of nucleophile, i. e., water or alcohol, the structures of olefin and phosphine ligand, and other reaction variables such as solvent, temperature, and carbon monoxide pressure.Under optimal conditions either unbranched products or branched products were obtained in high yields with high regioselectivities.For example, 4,4,4-trifluorobutyric acid (5a) was obtained in 93percent yield with 99percent regioselectivity by using PdCl2(dppf)-SnCl2 as the catalyst in the hydrocarboxylation of TFP while ethyl 2-methyl-3,3,3-trifluoropropionate (2a) was obtained in 96percent yield with 79percent regioselectivity in the hydroesterification of TFP by using PdCl2(PPh3)2 as the catalyst.Similarly, 3-(pentafluorophenyl)propionic acid (5b) was obtained in 93percent yield with 99percent regioselectivity in the hydrocarboxylation of PFS catalyzed by PdCl2(dppf), and methyl 2-(pentafluorophenyl)propionate (2b) was obtained in 89percent yield with 95percent regioselectivity in the hydroesterification of PFS catalyzed by PdCl2(PPh3)2.Possible mechanisms of the present reactions are discussed.The hydrocarboxylations of TFP and PFS may involve (hydroxycarbonyl)palladium(II) intermediates while the hydroesterifications of TFP and PFS may proceed via alkylpalladium(II) and acylpalladium(II) intermediates.
