Ligand sugar-substituted

The prototype industrial process based on this concept is the Ruhrchemie-Rhone Poulenc process for the hydroformylation of propylene to butanal94,219,220 (see Section 7.3.1). Because of the use of appropriately modified water-soluble ligands, the catalyst resides and operates in the aqueous phase. The particular features of this process are the positive energy balance and easy catalyst recovery, namely, the simply circulation of the aqueous catalyst solution. New types of water-soluble Ir and Rh complexes with tris(hydroxymethyl)phosphine222 were described, and the biphasic hydroformylation of 1-hexene was accomplished in ionic liquids.223 A cationic sugar-substituted Rh complex displays high regioselectivity to branched aldehydes.224... 

For systemic administration, the photosensitizer usually has to be delivered into the bloodstream by intravenous injection. Since the photosensitizer is a solid, this means that a solution or a stable suspension has to be provided. Metal complexes of the basic porphyrin and phthalocyanine nuclei are insoluble in water, so that some effort has to be made to render the system water soluble, or at least amphiphilic, by placing various substituents (e.g., S03H, C02H, OH, NR3+, polyether, aminoacid, sugar) on the periphery of the molecule. The aromatic character of the ligand offers a suitable opportunity for such substitutions to be made. Examples will appear frequently in the following sections. 

Albumin may be substituted with sugars, charged molecules, and (cyclic) peptides to obtain specificity for a certain cell type. The combination of receptor density on cells and the degree of substitution of receptor ligands on the albumin core protein greatly determines the cell-specific accumulation. To date, a set of carriers to all cell types of the liver is available (Table 4). 

Methoxy-2-vinylnaphthalene (MVN) 30 is hydrocyanated under the catalytic influence of Ni° complexes 31a-e of 1,2-diol phosphinites that are derived from readily available mono- and di-saccharides. The sugar backbone and substitution of the phosphorus-attached aryl groups have a pronounced effect on the reaction pathway. It is shown that electron-withdrawing groups on the aryl ligands dramatically increase the stereoselectivity. As much as 85% ee was obtained when... 

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