Rhodium/1 complexes containing

Complexation of (124) and (125) with [ Rh(COD)Cl 2] in the presence of Si(OEt)4, followed by sol-gel hydrolysis condensation, afforded new catalytic chiral hybrid material. The catalytic activities and selectivities of these solid materials have been studied in the asymmetric hydro-gen-transfer reduction of prochiral ketones and compared to that of the homogeneous rhodium complexes containing the same ligands (124) and (125) 307... 

Another structurally well characterized rhodium complex containing the phosphino(stibino)methane ligand as a chelate is [H3Rh2(r 2-C)2CCF3)2 r 2-(z -Pr)2P-CH2-Sb(z-Bu)2 2]PF6.101... 

The fact that adsorbed rhodium complexes contain one CF ion at most is remarkable, if one realizes that the actual concentration of Rh complexes with one Cl in moderately acid solutions cannot be high. According to Fenoglio et al. [11], exchange reactions between Cl ions and hydroxyls of the support of the type... 

Steric effects were also found to be important for determining the reactivity of rhodium complexes containing N-heterocyclic carbene (NF1C) ligands [47] (Scheme 10), which have been the subject of intense in-... 

Table 6.1 shows data for rhodium complexes containing xantphos ligands in which the electronic properties were systematically varied [13]. With few exceptions, we see that the rate of the hydroformylation reaction increases when the rhodium center is more electron deficient. This is as expected, since dissociation of... 

Figure 6.3 Rhodium complex containing a bidentate ligand with two different donor atoms.

Selke (58) for hydrogenation reactions with rhodium complexes containing these ligands. 

Direct addition of VI to chlorocarbonylbis(phosphine)rhodium complexes containing more basic phosphine ligands to yield optically active complexes of the type III did not occur. An optically active benzylrho-dium complex (X) was obtained, however, by adding (S)a-trifluoro-methylbenzylchlorosulfite (IX) to chlorocarbonylbis (diethylphenylphos-... 

EDITOR S NOTE In 1982, J Halpem (University of Chicago) reported that rhodium complexes containing chiral phosphine ligands catalyze the hydrogenation of olefinic substrates such as alpha-aminoacrylic acid derivatives, producing chiral products with very high optical yields. 

Studies in Asymmetric Synthesis, Preparation, Reactivity, and Solid-State Structures of Cationic Rhodium Complexes Containing a Chiral Amino-phosphine or Aminoarsine Ligand... 

At about the time of Wilkinson s discovery, new schemes were developed by others for the preparation and configurational correlation of chiral phosphines (lOa-e). The combination of advances in homogeneous catalysis and chiral phosphine technology prompted research on chiral phosphine complexes. Horner et al. (11) were the first to hypothesize in print that rhodium complexes containing optically active tertiary phosphine ligands should effect the asymmetric hydrogenation of unsymmetrically substituted olefins. 

Alternatively, an insoluble fluorous support, such as fluorous silica [43], can be used to adsorb the fluorous catalyst. Recently, an eminently simple and effective method has been reported in which common commercial Teflon tape is used for this purpose [44]. This procedure was demonstrated with a rhodium-catalyzed hydrosilylation of a ketone (Fig. 9.27). A strip of Teflon tape was introduced into the reaction vessel and when the temperature was raised the rhodium complex, containing fluorous ponytails, dissolved. When the reaction was complete the temperature was reduced and the catalyst precipitated onto the Teflon tape which could be removed and recycled to the next batch. 

On the other hand, divinyl-substituted organosilicon compounds in the presence of ruthenium and rhodium complexes containing or generating M-H and M-Si (M = Ru, Rh) bonds undergo competitive silylative coupling cyclization and polycondensation to give a mixture of oligomers and... 

There have been several articles reporting oxidative addition of various C-Cl bonds to Rh complexes [71-78]. Only a few Rh species, however, are capable of activating the C-Cl bond of nonactivated chloroarenes in a catalytic manner [73, 77, 78]. Rhodium complexes containing bulky basic phosphines, such as Cy3P and i-Pr3P, are excellent catalysts for the biphasic hydrogenolysis of the C-Cl bond of chloroarenes under mild conditions (Sect. 3.1) [77,78]. The mechanism of this catalytic C-Cl activation seems to be rather complex (Scheme 2). 

Rhodium complexes containing chiral organophosphorus ligands are of interest in view of their potential use as catalysts. With this application in mind, Viau et al. have prepared and characterised complex (148) (Scheme 30), which contains an ylide derivative (147) of the well-known R-BINAP ligand. ... 

Hessell ET, Jones WD (1992) Synthesis and structure of rhodium complexes containing a photolabile 72-carbodiimide ligand. 1,3-dipolar cycloaddition of phenyl azide to Tp Rh(CNR)2 (Tp = Hydrotris(3,5-dimethylpyrazolyl)borate). OrganometaUics 11 1496-1505... 

The most important process with the solvent water is the hydroformylation of propene to butyraldehydes, known as the Ruhrchemie/Rhone-Poulenc process. This reaction is catalyzed by a rhodium complex containing the water-soluble ligand triphenylphosphane trisulfonate (TPPTS). The aldehydes are formed with an annual capacity of approx. 3000001. 

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