Hydroformylation of alkenes with

HCo(CO)4 in Hydroformylation Reactions. As previously mentioned, HCo(CO)4 is a key intermediate in the homogeneous hydroformylation of alkenes with CO/H2 to aldehydes. Using HCo(CO)4 as the CO component, hydroformylation can be made stoichiometric when run under N2 as an inert atmosphere. 

Similar to the hydroacylation with aldehydes, the hydroformylation of alkenes with paraformaldehyde is efficiently catalyzed by the rhodium bicarbonate complex RhIl2(OOCOH)[P(r-Pr)3]2 and gives the corresponding aldehyde in neutral solution55. 

Fig. 32. Proposed mechanism for hydroformylation of alkenes with a rhodium catalyst.

Stoicheiometric hydroformylation of alkenes with [MnH(CO)s] has recently been reported. Treatment of 1,2-diphenyl 3,3-dimethylcyclo-propene in hexane under CO with [MnH(CO)s] at 55 °C gave a mixture of cis-(S7%) and trans-(l37o) aldehydes together with some alkane. The proposed mechanism is shown in Scheme 3. A chemically induced dynamic nuclear polarization (CIDNP) effect was observed in the H n.m.r. spectrum during the reaction and this was ascribed to the initial formation of an alkyl radical (10). The final step, reaction of a metal hydride with a metal acyl to give free aldehyde, is similar to that proposed in Co-catalysed hydro-... 

CK Brown, G Wilkinson. Homogeneous hydroformylation of alkenes with hy-dridocarbonyltris(triphenylphosphine)rhodium(I) as catalyst. J Chem Soc A 1970 2753-2764, 1970. 

Oxo or Hydroformylation and Hydroesterification. Reactions of alkenes with hydrogen and formyl groups are cataly2ed by HCo(CO)4... 

The main use of rhodium is with platinum in catalysts for oxidation of automobile exhaust emissions. In the chemical industry, it is used in catalysts for the manufacture of ethanoic acid, in hydroformylation of alkenes and the synthesis of nitric acid from ammonia. Many applications of iridium rely on... 

A lot of research has been published on hydroformylation of alkenes, but the vast majority of the effort has been focused on the chemistry of various metal-ligand systems. Quantitative kinetic studies including modeling of rates and selectivities are much more scarce. In this work, we present the approach to modeling of hydroformylation kinetics and gas-solubility. Hydroformylation of 1-butene with a rhodium-based catalyst was selected as a case study. 

Rhodium and cobalt participate in several reactions that are of value in organic syntheses. Rhodium and cobalt are active catalysts for the reaction of alkenes with hydrogen and carbon monoxide to give aldehydes, known as hydroformylation,281... 

Most recently new applications for substrate-controlled branched-selective hydroformylation of alkenes substituted with inductively electron-with drawing substituents have emerged. A recent example is the hydroformylation of acrylamide with a standard rhodium/triphenylphosphine catalyst, which yields the branched aldehyde exclusively (Scheme 4) [40]. Reduction of the aldehyde function furnishes 3-hydroxy-2-methylpropionamide, which is an intermediate en route to methyl methacrylate. 

Three generations of dendritic phosphines have been prepared from 3,5-diaminobenzoylglycine and 9-fluorenylmethoxycarbonyl-L-phenylalanine. The dendrimers were then attached to MBHA resin, treated with CH20 and Ph2PH, and converted to their Rh complexes. The polymer-supported complexes are excellent catalysts for the hydroformylation of alkenes, which could be recycled.283 The bidentate diphosphine A,A-bis-(P-(phosphabicyclo[3.3.1] nonan) methyl)aniline was prepared by phosphanomethylation of aniline. It forms a Rh-complex which is a highly regioselective catalyst in the hydroformylation of citronellene.284... 

The cA-PtCl2(diphosphine)/SnCl2 constitutes the system mostly used in catalyzed hydroformylation of alkenes and many diphosphines have been tested. In the 1980s, Stille and co-workers reported on the preparation of platinum complexes with chiral diphosphines related to BPPM (82) and (83) and their activity in asymmetric hydroformylation of a variety of prochiral alkenes.312-314 Although the branched/normal ratios were low (0.5), ees in the range 70-80% were achieved in the hydroformylation of styrene and related substrates. When the hydroformylation of styrene, 2-ethenyl-6-methoxynaphthalene, and vinyl acetate with [(-)-BPPM]PtCl2-SnCl2 were carried out in the presence of triethyl orthoformate, enantiomerically pure acetals were obtained. 

The monosulfonated PPh derivative, Ph2P(m-C6H4S03K) (DPM) and its rhodium complex, HRh(CO)(DPM)3 have been synthesized and characterized by IR and NMR spectroscopic techniques. The data showed that the structure was similar to [HRh(CO)(PPh3)3]. The catalytic activity and selectivity of [HRh(CO)(DPM)3] in styrene hydroformylation were studied in biphasic catalytic systems.420 421 Rh1 complexes [Rh(acac)(CO)(PR3)] with tpa (131), cyep (132), (126), ompp (133), pmpp (134), tmpp (135), PPh2(pyl), PPh(pyl)2, and P(pyl)3 were characterized with NMR and IR spectra. Complexes with (131), (132), and (126) were catalysts for hydrogenation of C—C and C—O bonds, isomerization of alkenes, and hydroformylation of alkenes.422 Asymmetric hydroformylation of styrene was performed using as catalyst precursor [Rh(//-0 Me)(COD)]2 associated with sodium salts of m-sulfonated diarylphosphines.423... 

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