Heptakis(2,3-di-O-methyl-6-O-sulfopropyl)-β-cyclodextrin:: A genuine supramolecular carrier for aqueous organometallic catalysis

The behavior of hepta kis(2,3-di-O-methyl-6-O-sulfopropyl)-beta-cyclodextrin as inverse phase transfer catalyst in biphasic Tsuji-Trost and hydroformylation reactions has been investigated. In terms of activity, this methylated sulfopropyl ether P-cyclodextrin is much more efficient than the randomly methylated P-cyclodextrin, which was the most active cyclodextrin known to date. From a selectivity point of view, the intrinsic properties of the catalytic system are fully preserved in the presence of this cyclodextrin as the chemo- or regioselectivity was found to be identical to that observed without a mass transfer promoter in the hydroformylation reaction. The efficiency of this cyclodextrin was attributed to its high surface activity and to the absence of interactions with the catalytically active species and the water-soluble phosphane used to dissolve the organometallic catalyst in the aqueous phase.