Rhodium complexes asymmetric hydrogenation

Ethane, (K)-l-cyclohexyl-L2-bis(diphenylphosphino)-rhodium complexes asymmetric hydrogenation, 6,253 Ethane, tetracyano-metal complexes, 2,263 Ethane, tetrakis(aminomethyl)-metal complexes, 2, 56 Ethane, tris[l, 1, l-(trisaminomethyl)]-complexes structure, 1,26... 

Phosphine, (2-bromophenyl)dichloro-, 2,991 Phosphine, (w-chloroalkyl)dichloro-, 2, 991 Phosphine, chlorodimethyl-, 2, 991 Phosphine, chloro(dimethylamino)-, 2, 991 Phosphine, chlorodiphenyl-, 2, 990 Phosphine, cyclohexyl(o-anisyl)methyl-rhodium complexes asymmetric hydrogenation, 6, 251 Phosphine, [(dialkylphosphino)alkyl]diphenyl-, 2, 994 Phosphine, dichloromethyl-, 2, 991 Phosphine, dichlorophenyl-, 2, 990 Phosphine, diethylphenyl-, 2, 992 Phosphine, dimethyl-, 2,992 Phosphine, dimethylphenyl-, 2,992 Phosphine, diphenyl-, 2, 992 Phosphine, ethyldiphenyl-, 2, 992 Phosphine, ethylenebis(diethyl-, 2, 993 Phosphine, ethylenebis(diphenyl-, 2,993 Phosphine, ethylenebis(phenyl-, 2,992 Phosphine, ethylidynetris[methylene(diphenyl-, 2,994 Phosphine, [(ethylphenylphosphino)hexyl]diphenyl-, 2, 994... 

Phosphine, methyl-n-propylphenyl-rhodium complexes asymmetric hydrogenation, 6,250 Phosphine, neomenthyldiphenyl-rhodium complexes asymmetric hydrogenation, 6,250 Phosphine, phenyl-, 2,992 Phosphine, o-phenylenebis(dimethyl-, 2,993 Phosphine, p-phenylenebis(diphenyl-, 2,993 Phosphine, seleno-metal complexes, 2,664 bidentatc, 2, 664 Phosphine, triaryl-photographic stabilizer, 6,103 Phosphine, tributyl-, 2, 992 oxide... 

Propane, (J )-1,2-bis(diphenylphosphino)-rhodium complexes asymmetric hydrogenation, 6, 251... 

Butane, 2,3-0-isopropylidene-2,3-dihydroxy-l,4-bis(diphenylphosphino)-rhodium complexes asymmetric hydrogenation, 251 Butane-2,4-dione, l,l,l-trifluoro-4-(2-thenoyl)-in uranium ore processing, 910 2-Butanone, 4-alkoxy-carbonylation... 

One of the success stories of transition metal catalysis is the rhodium-complex-catalyzed hydrogenation reaction. Asymmetric hydrogenation with a rhodium catalyst has been commercialized for the production of L-Dopa, and in 2001 the inventor, Knowles, together with Noyori and Sharpless, was awarded the Nobel Prize in chemistry. After the initial invention, (enantioselective) hydrogenation has been subject to intensive investigations (27). In general, hydrogenation reactions proceed... 

J. Am. Chem. Soc., 126. 4494. (i) Takacs, J.M., Chaiseeda, K. and Moteki, S.A. (2006) Rhodium-catalyzed asymmetric hydrogenation using self-assembled chiral bidentate ligands. Pure Appl. Chem., 78, 501. (j) Duckmanton, P.A., Blake, A.J. and Love, f.B. (2005) Palladium and rhodium ureaphosphine complexes Exploring structural and catalytic consequences of anion binding. Inorg. Chem., 44, 7708-7710. 

The bis(dioxolanyl)oxazolidinone 33 has been prepared from D-mannitol and evaluated as a chiral auxiliary <02MT749> and the diamine 34 has been examined as a ligand for rhodium catalysed asymmetric hydrogenation of diethyl itaconate <02JOU104>. Deracemisation of 2-benzylcyclohexanone by formation of an inclusion complex with the TADDOL compound 35 has been described and the mechanism clarified by X-ray structure determination of the complex <02T3401>. A production process for the bis(phosphine oxide) 36 has been patented <02USP6472539>. 

FIGURE 27 Self-assembly of diphosphine catalyst for asymmetric rhodium-complex-catalyzed hydrogenation the catalyst contains titanium as the assembly metal (96). (For a color version of this figure, the reader is referred to the Web version of this chapter.)... 

Rhodium-Catalyzed Asymmetric Hydrogenation of Olefins. MiniPHOS (1) can be used in rhodium-catalyzed asymmetric hydrogenation of olefinic compounds. The complexation with rhodium is carried out by treatment of 1 with [Rh(nbd)2]BF4in THF (eq 2). The hydrogenation of a-(acylamino)acrylic derivatives proceeds at room temperature and an initial H2 pressure of 1 or 6 atm in the presence of the 0.2 mol% MiniPHOS-Rh complex 2. The reactions are complete within 24—48 h to afford almost enantiomerically pure a-amino acids (eq 3). Itaconic acids, enamides, and dehydro-3-ami no acids can also be hydrogenated with excellent enantioselectivity (eq 4—6). 

Pracejus was fascinated by the idea of functionalizing cellulose as the cheapest chiral material and to use it in this form as a carrier for monovalent rhodium for asymmetric hydrogenation. Rh was shown by Wilkinson to be useful as a catalyti-cally active central metal in phosphane complexes. However, the catalytic activities of the new cellulose immobilized complexes in the hydrogenation of unsaturated amino acid precursors were low and the enantioselectivities did not exceed 35%... 

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