Ruthenium-catalyzed hydrogenation BINAP

Kitamura, M., Tokunaga, M., Pham, T., Lubell, W.D. and Noyori, R., Asymmetric synthesis of a-amino P-hydroxy phosphonic acids via BINAP-ruthenium catalyzed hydrogenation. Tetrahedron Lett., 36, 5769, 1995. 

Ruthenium-BINAP Catalysts. Ruthenium-catalyzed hydrogenations have been directed toward ketone reduction rather than alkene reduction, and... 

Scheme 1 Selected milestones in homogeneous ruthenium-catalyzed hydrogenation and transfer hydrogenation. BINAP = 2,2 - w-(diphenylphosphino)-l,l -binaphthalene. TsDPEN = Mp-Tosyl-1,2-diphenylethylenediamine...

Modification of the electronic and steric properties of BINAP, BIPHEMP, and MeO-BI-PHEP led to the development of new efficient atropisomeric ligands. Although most of them are efficient for ruthenium-catalyzed asymmetric hydrogenation [3], Zhang et al. have recently reported an ortho-substituted BIPHEP ligand, o-Ph-HexaMeO-BIPHEP, for the rhodium-catalyzed asymmetric hydrogenation of cyclic enamides (Scheme 1.2) [31]. 

BINAP core-functionalized dendrimers were synthesized by Fan et al. (36), via condensation of Frechet s polybenzyl ether dendritic wedges to 5,5 -diamino-BINAP (26—28). The various generations of BINAP core-functionalized dendrimers were tested in the ruthenium-catalyzed asymmetric hydrogenation of 2-[p-(2-methyl-propyl)phenyl]acrylic acid in the presence of 80 bar H2 pressure and in a 1 1 (v/v) methanol/toluene mixture. As later generations of the in situ prepared cymeneruthe-nium chloride dendritic catalysts were used, higher activities were observed (TOF values were 6.5, 8.3, and 214 h respectively). Relative to those of the BINAP... 

Ohta, T., Takaya, H., Kitamura, M., Nagai, K., Noyori, R. Asymmetric hydrogenation of unsaturated carboxylic acids catalyzed by BINAP-ruthenium(ll) complexes. J. Org. Chem. 1987, 52, 3174-3176. 

Kitamura, M., Tsukamoto, M., Bessho, Y., Yoshimura, M., Kobs, LI., Widhaim, M., Noyori, R. Mechanism of asymmetric hydrogenation of a-(acylamino)acrylic esters catalyzed by BINAP-ruthenium(ll) diacetate. J. Am. Chem. Soc. 2002, 124, 6649-6667. 

In addition to rhodium phosphane complexes, ruthenium phosphane complexes have also been successfully applied as catalysis for enantioseleetive hydrogenation of 2-acylamino-2-alkenoic acids and esters1 71,72b 3, enol acetates 18 (R = i-Pr E = COOEt X = OCOCH3 98% ee with BINAP)137, and itaeonic acid138. The absolute configuration of the products from the ruthenium-catalyzed reactions shown below is opposite to that obtained with the corresponding rhodium catalysts. 

A ruthenium complex with the dendrimer BINAP ligand obtained from aromatic polyethers 55 catalyzed hydrogenation of 2-[p-(2-methylpropyl)phe-nyl] acrylic acid to ibuprofen at an optical selectivity of 99% in a methanol-toluene solution the activity of the dendrimer complex was twice as high as that of a low molecular weight analogue [138],... 

T Ohta, H Takaya, M Kitamura, K Nagai, R Noyori. Asymmetric hydrogenation of unsaturated carboxyhc acids catalyzed by BINAP-ruthenium(II) complexes. J Org Chem 52 3174-3176, 1987. 

Kitamura M, Hsiao Y, Ohta M, Tsukamoto M, Ohta T, Takaya H, Noyori R (1994) General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium(II) complexes. J Oig Chem 59 297-310... 

Figure 4.35 Chiral BINAP-functionalized Janus dendrimers for the ruthenium-catalyzed asymmetric hydrogenation.

Enantioselective catalytic hydrogenation. The ruthenium(II) complexes of (R)- and (S)-l, bearing a chiral BINAP ligand, catalyze asymmetric hydrogenation of N-acyl-l-alkylidenetetrahydroisoquinolines to give (1R)- or (lS)-tetrahydroiso-quinolines in 95-100% ee.1 Thus the (Z)-enamide (2), prepared by acylation of 3,4-dihydropapaverine, is hydrogenated in the presence of (R)-l to (1R)-tetrahydroisoquinolines (3). The enantiomeric (lS)-3 is obtained on use of (S)-l as catalyst. 

Asymmetric reduction of carbonyl via hydrogenation catalyzed by ruthenium(II) BINAP complex. 

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