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Rhodium complex derivative

Subsequently, it was shown that rhodium complexes derived from diphosphi-nites, diphosphonites, and diphosphites - as well as hybrid ligands - are similarly active and selective to diphosphines [46 i],... [Pg.21]

The hydrogenation of ketones with O or N functions in the a- or / -position is accomplished by several rhodium compounds [46 a, b, e, g, i, j, m, 56], Many of these examples have been applied in the synthesis of biologically active chiral products [59]. One of the first examples was the asymmetric synthesis of pantothenic acid, a member of the B complex vitamins and an important constituent of coenzyme A. Ojima et al. first described this synthesis in 1978, the most significant step being the enantioselective reduction of a cyclic a-keto ester, dihydro-4,4-dimethyl-2,3-furandione, to D-(-)-pantoyl lactone. A rhodium complex derived from [RhCl(COD)]2 and the chiral pyrrolidino diphosphine, (2S,4S)-N-tert-butoxy-carbonyl-4-diphenylphosphino-2-diphenylphosphinomethyl-pyrrolidine ((S, S) -... [Pg.23]

COBALT AND RHODIUM COMPLEXES DERIVED FROM OFCOT AND PERFLUOROBICYCLO[4.2.0]OCTA-2,4,7-TRIENE... [Pg.217]

E. Pentamethylcyclopentadienyl Cobalt and Rhodium Complexes Derived from OFCOT... [Pg.225]

An N-heterocyclic carbene rhodium complex derived from L-proline has been reported (Scheme 10). The rhodium complex 9 is active catalyst for the addition reaction of arylboronic acids to aldehydes, albeit with low ee s (21% at best) [29]. [Pg.124]

The Shi and Crabtree groups have found that iridium and rhodium complexes derived from BINAM (l,T-binaphthyl-2,2 -diamine) are also capable of the transformation. While Shi s Rh catalyst 37 [81] gave similar results to those reported by Gade, Crabtree s Ir catalyst 38 [82] was less effective, providing optical induction of only 60%. [Pg.188]

P solid-state NMR spectra were used to characterise Si02-tethered rhodium complexes derived from RhCl(PPh3)3 or RhH(CO)(PPh3)3.210... [Pg.141]

In 2005, Sames and co-workers reported the highly selective (>50 1) C2-arylation of NH-free indoles using a rhodium complex derived from an electron-deficient phosphine as the catalyst, CsOPiv as a base, and iodoar-enes as coupling partners (Scheme 37, 05JA4996). Mechanistic studies revealed that a highly electrophilic Ar-Rh(III) complex was formed in situ through the oxidative addition of aryl iodide to Rh(I) (Scheme 38). Then the displacement of the phosphine ligand by indoles takes place, followed by... [Pg.331]

Notably, an independently synthesized air-stable rhodium complex derived from preligand 24 was shown to be catalytically competent furthermore, spectroscopic data indicated the formahon of complex 28. Therefore, a mechanism was proposed that proceeded via an in situ generation of the corresponding phosphinite, with subsequent cyclometallation. [Pg.316]

There are rather few water-soluble hydrogenation catalysts. A number of rhodium complexes derived from ligands such as (PH2PCH2CH2)2NC0C6H4S03" are active in this way. " Catalysts have been developed for hydrogenation of ketonescarboxylic acids/ esters/ nitriles/ and nitro compounds. [Pg.303]

Si02-tethered rhodium complexes, derived from Rh(CO)2(acac) and 3-(mercapto) propyl- and 3-(l-thioureido)propyl-functionalized silica gel, were used as catalysts in the hydroformylation of various vinyl arenes and vinyl acetate. Conversions, che-moselectivity, and regioselectivity obtained with the Si02-tethered catalysts were comparable with those of the well-known homogeneous rhodium catalysts [85]. [Pg.177]

Rhodium complexes derived from chelating bisphosphines anchored to an asymmetric, ancillary Cp-Re complex exhibit moderate enantioselectivity in the hydrosiiation of phenyl/alkyl ketones with Ph2SiH2. A tra i-chelating, planar-chiral bisphosphine 40, based on a biferrocenyl motif, forms Rh complexes that are... [Pg.29]

Cri.i iN. W. R.. and Y. SuGi Asymmetric Hydrogenation Catalyzed by Diphos-phinite Rhodium Complexes Derived From A Sugar. Tetrahedron Letters 1978, 1635. [Pg.326]


See other pages where Rhodium complex derivative is mentioned: [Pg.165]    [Pg.36]    [Pg.18]    [Pg.156]    [Pg.811]    [Pg.91]    [Pg.70]    [Pg.70]    [Pg.48]    [Pg.70]    [Pg.71]    [Pg.157]    [Pg.147]    [Pg.41]    [Pg.389]    [Pg.242]    [Pg.51]    [Pg.118]    [Pg.393]   


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