Georges Fremy

A further breakthrough in biphasic, rhodium-catalyzed hydroformylation: the use of Per(2,6-di-O-methyl)-β-cyclodextrin as inverse phase transfer catalyst

Abstract Solvent free biphasic hydroformylalion of various water-insoluble terminal olefins can be achieved in high yields and sclcctivitics by using a water-soluble rhodium/triphenylphosphine trisulfonate catalyst and per(2,6-di-o-mclhyl)-β-cyclodcxtrin as inverse phase transfer catalyst. The catalytic activities were up to ten times higher than those observed without pcr(2,6-di-o-methyl)-β-cyclodextrin.

A new, highly selective, water-soluble rhodium catalyst for methyl acrylate hydroformylation

Abstract Hydroformylation of methylacrylate to α-aldehyde can be achieved in a two-phase system in the presence of two new water-soluble phosphines. High yields and selectivities of α-aldehyde (ca. 80% with a α/β ratio of 1:20) were obtained. Spectroscopic studies have been carried out and some new rhodium complexes formed in situ in catalytic systems have been identified.

An unusual enhancement of catalytic activity in biphasic catalysis: The rhodium catalyzed hydroformylation of acrylic esters

Abstract The hydroformylation of various acrylic esters in a two-phase system using a water soluble rhodium complex of trisulfonated triphenylphosphine as catalyst was investigated. The hydroformylation rates of acrylates relatively soluble in water are surprisingly higher in a biphasic system than those observed in a homogenous single-phase system; rate enhancement by a factor of 2–14 can be reached. The role of water on the enhancement of catalytic activity is discussed.

A very useful and efficient Wacker oxidation of higher α-olefins in the presence of per(2,6-di-O-methyl)-β-cyclodextrin

Abstract Oxidation of higher α-olefins (C 8 C 16 ) in a two phase system with multicomponents catalytic system, i.e. PdSO 4 /H 9 PV 6 Mo 6 O 40 /CuSO 4 and per(2,6-di- O -methyl)- β -cyclodextrin) gives the corresponding 2-ketones in high yields (>90 %).