Industrial application of asymmetric reactions catalyzed by BINAP-metal complexes

Homochiral metal–organic frameworks as heterogeneous catalysts

Homochiral metal–organic frameworks (HMOFs) are attractive materials for asymmetric catalysis because they possess high surface area and uniform active sites.

Asymmetric Hydrogenation of Aryl Ketones Mediated by a Copper Catalyst

[reaction: see text] A novel asymmetric hydrogenation protocol using a copper catalyst is reported. A Cu(I) complex in the presence of nonracemic BDPP hydrogenates aryl ketones with moderate to high enantioselectivity.

Polymer-supported catalysts: enantioselective hydrogenation and hydrogen transfer reduction

Different types of heterogenized catalysts were involved in asymmetric reactions. Hydrogen transfer reduction was performed with amino alcohols derived from poly((S)-(GMA-co-EGDMA or DVB)) and hydrogenation with BINAP grafted onto PEG or copolymerized with isocyanates as ligands. Attempts of catalysts recycling are reported.

2,2',5,5'-tetramethyl-4,4'-bis(diphenylphoshino)-3,3'-bithiophene: a new, very efficient, easily accessible, chiral biheteroaromatic ligand for homogeneous stereoselective catalysis

The four-step straightforward synthesis of enantiopure (+)- and (-)-2,2',5,5'-tetramethyl-4,4'-bis-(diphenylphoshino)-3,3'-bithiophene (tetraMe-BITIOP), a new C2-symmetry chelating ligand for transition metals, is described, starting from 2,5-dimethylthiophene. The complexes of this electron-rich diphosphine with Ru(II) and Rh(I) were used as catalysts in some homogeneous hydrogenation reactions of prostereogenic carbonyl functions of alpha- and beta-ketoesters, of prostereogenic carbon-carbon double bonds of substituted acrylic acids, and of N-acetylenamino acids. The enantiomeric excesses were found to be excellent in all the experiments and comparable with the best results reported in the literature for the same reactions, carried out under similar experimental conditions, with the metal complexes of the most popular chiral diphosphine ligands as catalysts.

Me-DuPHOS-Rh-Catalyzed Asymmetric Synthesis of the Pivotal Glutarate Intermediate for Candoxatril

A greatly improved process has been developed for synthesis of the glutarate derivative 2, a key intermediate required for Pfizer's drug candoxatril. The cationic (R,R)-Me-DuPHOS-Rh catalyst was found to allow highly efficient and enantioselective hydrogenation of a unique carboxylate substrate (5) to afford the desired product in >99% ee and high yield (95%). The robust nature of the process was validated on a 12 kg reaction scale. A novel mechanism for the hydrogenation process is proposed. Through use of a labile eta(6)-benzene-Rh-Me-DuPHOS complex, the postulated catalytic intermediates have been synthesized by independent means. Detailed spectroscopic analyses of these intermediates corroborate the mechanistic hypotheses. Interconversion of these key catalytic intermediates has been demonstrated.