Water-Soluble Rhodium-Phosphine Complex Catalytic Systems

Water-Soluble Rhodium-Phosphine Complex Catalytic Systems 

The water-soluble rhodium catalyst is a rhodium-phosphine complex HRh(CO)(TPPTS)3. Ths solubihty of TPPTS in water is about 1 l kg of water. In general, the advantages of RCH/RP can he described as follows  

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Hydroaminomethylation of alkenes occurred to give both n- and /. so aliphatic amines catalyzed by [Rh(cod)Cl]2 and [Ir(cod)Cl]2 with TPPTS in aqueous NH3 with CO/H2 in an autoclave. The ratio of n-and /.soprimary amines ranged from 96 4 to 84 16.178 The catalytic hydroaminomethylation of long-chain alkenes with dimethylamine can be catalyzed by a water-soluble rhodium-phosphine complex, RhCl(CO) (Tppts)2 [TPPTS P(m-C6H4S03Na)3], in an aqueous-organic two-phase system in the presence of the cationic surfactant cetyltrimethy-lammonium bromide (CTAB) (Eq. 3.43). The addition of the cationic surfactant CTAB accelerated the reaction due to the micelle effect.179... 

A major aspect of the chemistry of both Rh1 and Ir1 is the formation of tertiary phosphine complexes. Much used are the phosphines PPh3, PPr 3, PMe3 and mixed phosphines such as PMe2Ph. Triphenylphosphine is used in catalytic hydrofor-mylations of alkenes, while water soluble phosphines, notably P(QH4S03H)3, are used in two-phase systems. The important fra s,-chlorocarbonylbis(triphenylphos-phine)rhodium(I) is obtained as yellow crystals on reduction of RhCl3(aq) in EtOH with formaldehyde. It can also be made by the reactions... 

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