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Iridium-catalyzed asymmetric hydrogenation of olefins.

Iridium-catalyzed asymmetric hydrogenation of olefins.

Accounts of chemical research (2007-08-04)

Stephen J Roseblade, Andreas Pfaltz

ABSTRACT

Asymmetric hydrogenation is one of the most important catalytic methods for the preparation of optically active compounds. For a long time the range of olefins that could be hydrogenated with high enantiomeric excess was limited to substrates bearing a coordinating group next to the C+C bond. We have found a new class of catalysts, iridium complexes with chiral P, N ligands, that overcome these limitations. For a wide range of unfunctionalized olefins, excellent enantioselectivities could be achieved. Because these catalysts do not require the presence of any particular functional group in the substrate, they considerably broaden the scope of asymmetric hydrogenation. In addition, promising results were also obtained with certain functionalized alkenes, furans, and benzofurans.

MATERIALS

Product Number

Brand

Product Description

Sigma-Aldrich

Iridium, evaporation slug, diam. × L 0.6 cm × 1.2 cm, 99.9% trace metals basis

Sigma-Aldrich

Iridium, foil, thickness 0.25 mm, 99.9% trace metals basis

Sigma-Aldrich

Iridium, powder, 99.9% trace metals basis

Iridium, foil, light tested, 25x25mm, thickness 0.05mm, as rolled, 99.9%

Iridium, foil, 25x25mm, thickness 0.15mm, as rolled, 99.9%

Iridium, wire reel, 0.2m, diameter 0.075mm, as drawn, 99.9%

Iridium, rod, 50mm, diameter 3.0mm, as drawn, 99.9%

Iridium, wire reel, 0.2m, diameter 0.125mm, as drawn, 99.5%

Iridium, wire reel, 0.05m, diameter 0.075mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 0.15mm, as drawn, 99.9%

Iridium, wire reel, 0.025m, diameter 2.0mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 0.1mm, as drawn, 99.9%

Iridium, wire reel, 0.2m, diameter 0.125mm, as drawn, 99.9%

Iridium, wire reel, 0.05m, diameter 0.1mm, as drawn, 99.9%

Iridium, microfoil, disks, 25mm, thinness 0.1μm, specific density 224μg/cm², permanent mylar 3.5μm support, 99.9%

Iridium, wire reel, 0.1m, diameter 0.25mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 1.0mm, as drawn, 99.9%

Iridium, foil, 25x25mm, thickness 0.25mm, as rolled, 99.9%

Iridium, foil, 0.05m coil, thickness 0.05mm, coil width .5mm, as rolled, 99.9%

Iridium, wire reel, 0.05m, diameter 0.8mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 0.2mm, as drawn, 99.9%

Iridium, foil, 25x25mm, thickness 0.125mm, as rolled, 99.9%

Iridium, foil, 0.025m coil, thickness 0.05mm, coil width .5mm, as rolled, 99.9%

Iridium, wire reel, 0.1m, diameter 0.38mm, as drawn, 99.9%

Iridium, wire reel, 0.2m, diameter 0.1mm, as drawn, 99.9%

Iridium, wire reel, 0.2m, diameter 0.15mm, as drawn, 99.9%

Iridium, wire reel, 0.05m, diameter 2.0mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 0.5mm, as drawn, 99.9%

Iridium, wire reel, 0.2m, diameter 0.25mm, as drawn, 99.9%

Iridium, wire reel, 0.1m, diameter 0.075mm, as drawn, 99.9%