Rhodium tris triphenylphosphine carbonyl

Rhodium-catalysed addition (10) of hydridosilanes (Chapter 17) to a/3-unsaturated carbonyl compounds can be performed regioselectively, to afford either the product of 1,2-addition, or, perhaps more usefully, that of 1,4-addition, i.e. the corresponding silyl enol ether this latter process is an excellent method for the regiospecific generation of silyl enol ethers. Of all catalyst systems investigated, tris(triphenylphosphine)rhodium(l) chloride proved to be the best. 

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 ... 

Recently, it has been discovered that catalysis by rhodium compounds is more effective than by the older cobalt catalyst when tris(triphenylphosphine)rhodium chloride is treated with carbon monoxide, the catalyst bis(triphenylphosphine)rhodium carbonyl chloride is formed. This catalyst is very effective under very mild conditions (49-51). It is believed that the tr-ir rearrangement is also important with this catalyst and operates in a manner analogous to that in the cobalt-catalyzed process, since stablization of the cr complex has been shown to lead to olefin isomerization and lower linear selectivity (52). 

The tris(triphenylphosphine) rhodium carbonyl hydride complex also was used via ligand exchange to obtain known chelate complexes of bisphosphines... 

The studies of Wilkinson et al. included IR and H-l NMR spectroscopy of the intermediate species of this catalyst system (7). This led to recognizing tris(triphenylphosphine)rhodium(I) carbonyl hydride (D) as the key stable rhodium complex. The reactive trans-bis-(triphenylphosphine)rhodium(I) carbonyl hydride (E) resulting via the dissociation of this complex... 

Since there were no known definitive studies of the crucial equilibria between the tris-(triphenylphosphine)- and bis-(tri-phenylphosphine)rhodium(I) carbonyl hydride complexes, it was decided to study such equilibria by P-31 NMR spectroscopy. The... 

Tris(triphenylphosphine) rhodium(l) Carbonyl Hydride-Plus-Triphenylphosphine Systems... 

Chelate Complexes Derived from Tris(triphenylphosphine)rhodium(l) Carbonyl Hydride and Bisphosphines... 

As indicated in the introduction, bis-l,3-diphenylphosphino-propane (dppp) and bis-l,2-diphenylphosphinoethane (dppe) were reacted with tris(triphenylphosphine)rhodium(II) carbonyl hydride in toluene-deuterobenzene solution to derive cis-chelate complex hydroformylation catalysts. These complexes were expectedly non-selective terminal hydroformylation catalysts for 1-butene hydroformylation (see Table I) because of their cis-stereochemistry. They were also somewhat less active due to their specific structural features. The structure of these complexes in solution was studied in detail by P-31 NMR spectroscopy. 

Figure 13 illustrates the temperature dependence of the spectra of the solution derived by reacting 1 mol of tris(triphenylphosphine)-rhodium(I) carbonyl hydride with 6 mol of dppp. The maintenance of the narrow line width of the intense doublet signal at 16.1 ppm shows that the bicyclic complex does not dissociate up to 90°C. On the other hand, broadening signals of the complex spectrum of the monocyclic complex and that of the singlet signal of free dppp indi-... 

Since the position of the aldehyde function on the alkyl chain will probably affect the quality of a fixation, we have studied the regioselectivity of the synthesis of aldehyde-functionalized mono- and trialkoxysilanes, using rhodium-hydrido-carbonyl-tris(triphenylphosphine) as catalyst. In general, the hydroformylation of the terminal double bond in organoalkenylsilanes results in the formation of isomeric aldehydes (Eq. 1). 

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... 

P3ClRhCs4H4s. Rhodium(I), chlorotris(tri-phenylphosphine)-, 28 77 P3CI2OSCJ4H45, Osmium(II), dichlorotri(tri-phenylphosphine)-, 26 184 P3CI2OSSC55H45, Osmium(II), dichloro(thio-carbonyl)tris(triphenylphosphine)-, 26 185... 

When reacting alkenes with triethylsilane it is necessary to keep in mind that the PdCl2/Et3SiH combination also promotes the double bond isomerization of monosubstituted aliphatic olefins and a-alkylidene cyclic carbonyl compounds are isomerized to a,/3-unsaturated cyclic carbonyls with tris(triphenylphosphine) rhodium chloride. ... 

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. 

Tris(triphenylphosphine) rhodium carbonyl hydride 1,3,5-Trithiane Trithiocarbonicacid... 

Tris(triphenylphosphine)-rhodium carbonyl hydride Carbonylhydrotris(triphenylpho sphine)rhodium C55H460P3Ph 17185-29-4 918.781 ye cry 121 1.33 si bz, chi... 

As shown by the data of Table I, adding increasing amounts of the three phosphines used in the present studies to tris(tri-phenylphosphine)rhodium(I) carbonyl hydride produces catalyst systems of reduced activity as indicated by the reduced reaction rate. As expected, an increasing excess of triphenylphosphine results in an increased 1-butene hydroformylation selectivity towards the n-... 

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