Chloro-tris- rhodium

The hydrogenation of vinylnaphthalene 1 was performed by mixing solid chloro-tris(triphenylphosphine)rhodium catalyst (7.0 mg, 7.6 pmol) with solid 2-vinyl-naphthalene (350 mg, 2.27 mmol, substrate Rh=300 l), both fine powders. The mixture was placed, with a stirring bar, into a 22 mm diameter flat-bottomed glass finer in a 160-mL high-pressure vessel, which was then sealed and warmed to 33 °C in a water bath. The vessel was flushed and pressurized with H2 to 10 bar. This was considered the start of the reaction. Carbon dioxide was then added to a total pressure of 67 bar. After 30 min, the vessel was removed from the water bath and vented. The product mixture was dissolved in CDCI3 and characterized by H NMR spectroscopy. 

Related Reagents. Bis(bicyclo[2.2.1 ]hepta-2,5-diene)rho-dium Perchlorate Bis(bicyclo[2.2.1]hepta-2,5-diene)rhodium Perchlorate-(i )-l-(5 )-l, 2-Bis(diphenylphosphino)ferrocenyl-ethanol 2,2 -Bis(diphenylphosphino)-l,r-binaphthyl Chloro-tris(triphenylphosphine)rhodium(I). 

Finally, allenes can be hydrogenated to alkenes in moderate yields with chloro-tris(triphenylphosphine)rhodium in benzene at RT. The reaction is stereoselective. 

Similarly, intramolecular [4 4- 2] cycloaddition of unactivated dienynes is also catalyzed and dramatically accelerated by low-valent rhodium complexes, e.g., Wilkinson s catalyst [chloro-tris(triphenylphosphane)rhodium] and phosphite analogs, under mild conditions46. Thus, ( , )-l-(2-propynyloxy)-2,4-hexadiene (3, Z = O) and similar dienynes, with 5 mol% of chlorotris(tri-phenylphosphane)rhodium in 2,2,2-trifluoroethanol for 30 minutes at 55 C. give up to quantitative yield of the cycloadducts with excellent to complete diastereoselection. According to control... 

Zu drastische Reaktionsbedingungen Entaktivierung des Katalysators. Infolgc Chlorhydrogenolyse ent-steht Dichloro-hydrido-tris-[triphenylphosphin]-rhodium und infolge Decarbonylierung von Allyl-alkohol, Estern, DMF oder 1,4-Dioxan Carbonyl-chloro-tris-[triphenylphosphin]-rhodium... 

Ein strukturbedingter Isotopenaustausch kann vielfach durch homogene Deuterierung mit Chloro-tris-[triphenyl-phosphin]-rhodium (Wilkinson-Katalysator) vermieden werden (s.Tab. 32, S. 104). 

A mixture of methyl crotonate, a slight excess of trimethylsilane, and chloro-tris(triphenylphosphine)rhodium(I) warmed to 60° -> product. Y 77%. F. e. s. E. Yoshii et al., Chem. Pharm. Bull. 22, 2767 (1974). 

In 1958, Russian chemists [31] reported that chloroplatinic acid-catalyzed hydrosilylation of a,/3-unsaturated carbonyl compounds takes place in a 1,4-fashion. Recently, it has been disclosed [35] that highly selective 1,2- as well as 1,4-addition of hydrosilanes to ajS-unsaturated terpene ketones can be achieved by using chloro-tris(triphenylphosphine)rhodium(I) (7), the selectivity depending markedly on the nature of the hydrosilane employed as described in Section 4.1. This achievement has resulted in studies on two kinds of selective asymmetric hydrosilylation of a, unsaturated carbonyl compounds by making use of either selective 1,4-addition or 1,2-addition the 1,4-addition induces asymmetry on a jS-carbon to afford optically active saturated carbonyl compounds, while the 1,2-addition gives optically active allylic alcohols. 

C9H27Br2NiP3, Dibromotris(trimethylphosphine)nickel(II), 40B, 1028 C9H27ClP3Rh, Chlorotris(trimethylphosphine)rhodium(I), 46B, 1250 C9H27Cl2P3Pt, Chloro-tris(trimethylphosphine)platinumdI) chloride, 46B, 1246... 

Bis-[triphenylphosphin]-carbonyl-organo-rhodium(0) bzw. -iridium(O) sind aus den entsprechenden Dichloro-Komplexen bzw. Carbonyl-tris-[triphenyl-phosphin]-rhodium(0) bzw.-iridium(O) aus den Chloro-Komplexen zuganglich7 ... 

After the resolution of 1-2-chloro-ammino-diethylenediamino-cobaltie chloride many analogous resolutions of optically active compounds of octahedral symmetry were carried out, and active isomers of substances containing central cobalt, chromium, platinum, rhodium, iron atoms are known. The asymmetry is not confined to ammines alone, but is found in salts of complex type for example, potassium tri-oxalato-chromium, [Cr(Ca04)3]K3, exists in two optically active forms. These forms were separated by Werner2 by means of the base strychnine. More than forty series of compounds possessing octahedral symmetry have been proved to exist in optically active forms, so that the spatial configuration for co-ordination number six is firmly established. 

Previous work has shown that the electronic characteristics of the benzene substituent in triarylphosphine chlororhodium complexes have a marked influence on the rate of olefin hydrogenation catalyzed by these compounds. Thus, in the hydrogenation of cyclohexene using L3RhCl the rate decreased as L = tri-p-methoxyphenylphosphine > triphenylphosphine > tri-p-fluorophenylphosphine (14). In the hydrogenation of 1-hexene with catalysts prepared by treating dicyclooctene rhodium chloride with 2.2-2.5 equivalents of substituted triarylphosphines, the substituent effect on the rate was p-methoxy > p-methyl >> p-chloro (15). No mention could be found of any product stereochemistry studies using this type of catalyst. 

Nitrosylpentaamminecobalt(II) chloride, synthesis 49 cts-Bromoamminebis (ethylenediamine) cobal t (111) bromide, CIS- and trans-aquoamminebis(ethylenediamine)cobalt(IIl) bromide, and cis- and triphenylphosphine)rhodium and chloro-carbonylbis(triphenylarsine)rhodium, synthesis 56 Sodium hexachlororhodate(III) 2-hydrate and potassium hexachlororhodate(III) 1-hydrate, synthesis 57 Ammonium hexachloroiridate(IV), synthesis 58 Resolution of the tris(l,10-phenanthroline)nickel(II) ion, synthesis 59... 

Steckhan et al. demonstrated convincingly that systems that fulfil these conditions are tris(2,2 -bipyridyl)rhodium complexes [57] and, more effectively, substituted or unsubstituted (2,2 -bipyridyl(pentamethylcyclopentadienyl)chloro or aquo rhodium complexes [58] (see Scheme 1). Electrochemical reduction of these complexes at potentials between —680 mV and —840 mV vs. SCE leads to the formation of hydrido rhodium complexes. Strong catalytic effects observed in cyclic voltammetry and preparative electrolysis indicate a very fast hydride transfer from the hydrido complex to NAD(P) under formation of only 1,4-NAD(P)H and the starting complex as shown in the following reaction scheme [58] ... 

The successful synthetic application of this electroenzymatic system has been demonstrated for the in situ electroenzymatic reduction of pyruvate to D-lactate using the NADH-dependent D-lactate dehydrogenase. Electrolysis at —0.6 V vs. Ag/AgCl reference electrode of 50 ml of a 0.1 M tris-YLC buffer of pH 7.5 containing pentamethylcyclopen-tadienyl-2,2 -bipyridine-chloro-rhodium(III) (1 x 10 M), NAD (2 x 10 M), pyruvate (2 X 10 M), and 1300 units D-lactate dehydrogenase (divided cell, carbon foil electrode) after 3 h resulted in the formation of D-lactate (1.4 x 10 M) with an enantiomeric excess of 93.5%. This means that the reaction occurred at a rate of 5 turnovers per hour with respect to the mediator with a 70% turnover of the starting material. The current efficiency was 67% [62] (Fig. 12). 

HYDROGENATION CATALYSTS Bis-(pyridine)dimethylformamidedichlororho-dium borohydride. Iron pentacarbonyl. Lindlar catalyst. Nickel boride. Palladium-on-calcium carbonate. Rhodium-on-alumina. Rhodium-on-carbon. Ruthenium trichloride hydrate. Triron dodecacar-bonyl. Tris(triphenylphosphine)chloro-... 

DECARBONYLATION Simmons-Smith reagent. Tris(triphenylphosphine)chloro-rhodium. 

The reaction occurs at room temperature or in refluxing benzene or toluene. Yields are generally in the range 65-90%. See also Tris-(triphenylphosphine chloro-rhodium. 

Diazopropenes bearing, for example, chloro substituents on the double bond can readily be purified by short-path distillation. Subsequent vinylcyclopropanations are carried out at low temperature using copper(II) catalysts such as bis(trifluoroacetonato)copper(II), copper(II) tri-fluorosulfonate and copper(II) trifluoroacetate in the presence of a 15-60-fold excess of the alkene. The dimer of rhodium(Il) acetate (0.1 mol%, tenfold excess of alkene), however, is generally more effective, leading to higher yields in this reaction (see Houben-Weyl, Vol. El9b, Table 100). 

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