Beyond Nature's Chiral Pool: Enantioselective Catalysis in Industry

Abstract

Enantioselective catalysts produce organic compounds in enantiomerically enriched form. They are highly efficient tools for the synthesis of biologically active materials, such as pharmaceuticals and crop-protection chemicals, in which enantiomeric purity can be critical. The design of chiral ligands is the key to developing new enantioselective catalysts. Three unusual families of ligands have been used to develop practical technology for enantioselective hydrocyanation of olefins, ring-opening of epoxides, and hydrogenation of various compounds.

(±)-8-Phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine

“…For efficient asymmetric catalysis development of new effective chiral ligands is essential (Nugent, RajanBabu & Burk, 1993). Although various kinds of chiral-P ligands have been prepared, chiral phosphonites are rare (Richter, 1983;Kagan, 1985).…”

Recent Advances in Substrate-Controlled Asymmetric Induction Derived from Chiral Pool α-Amino Acids for Natural Product Synthesis

“…This strategy is one of the best methods available to synthetic organic chemists for establishing pivotal stereocenters in optically active compounds [3][4][5][6][7]. The chiral pool is a versatile tool, comprising naturally occurring chiral molecules such as carbohydrates, amino acids, terpenes, alkaloids, and hydroxyacids [2,6].…”

“…Chiral pool materials are also inexpensive and commercially available, making them adequate for use in accessing natural products and bioactive compounds [2]. The usage of the chiral pool in asymmetric synthesis can be classified in three general categories, as shown in Figure 1: (a) chiral sources, used as building blocks containing built-in stereocenters for target molecules; (b) chiral devices, employed as useful tools for enantioselective catalysts and auxiliaries; and (c) chiral inducers, applied to the generation of new stereocenters in a substrate-controlled manner [1][2][3][4][5][6][7]. The chiral inducer strategy is a highly efficient method to exploit advantages of both the chiral source and device approach at the same time.…”

Enantioselectivity on Surfaces

“…These complexes are not enantiomers of one another and thus can be separated by exploiting differences in their physical properties. [6] Once the two complexes are separated, R 2 can be removed and separated to produce pure samples of R 1 and S 1 . The desired enantiomer can then be used, whereas the undesired enantiomer is either discarded or, if possible, racemized and subjected to further enantioselective purification by complexation with R 2 .…”