An Asymmetric Catalyst

The bright future of stereoselective synthesis of co-ordination compounds

“…Enantioselective catalysis was for the first time successful in the laboratory only in the 1950's. 2 It is noteworthy that a preponderant number of the laboratory enantioselective catalysts and also quite a few natural enzymes that perform enantioselective syntheses contain metal centres, which are often the active sites of the catalyst or the enzyme.…”

In phase with synthesis

“…The initial success of catalytic asymmetric hydrogenation by Knowles 3 was a direct result of the earlier work by Wilkinson on a soluble hydrogenation catalyst, the synthesis of which would not have been possible without earlier and more fundamental work on metal complexes. And the enantioselectivities achieved by these new molecular catalysts were useful -showing that this was a more promising avenue to explore than earlier attempts to insert metals into a chiral heterogeneous support 4 . Subsequently, the work of Sharpless 5 on asymmetric oxidations showed that useful enantioselectivites were not limited to hydrogenation reactions.…”

Asymmetric Hydrogenation

“…Heterogeneous hydrogenation is technically simple and has a longer history than homogeneous hydrogenation. In 1956, Akahori et al reported the asymmetric hydrogenation of azalactones in the presence of silk-fibroin-supported palladium (Scheme 1) [1]. This pioneering work was later extended to the hydrogenation of prochiral ketones using a Raney nickel or platinum catalyst that was modified by chiral auxiliaries, such as tartaric acid or cinchona alkaloids.…”