Enantiomerically pure compounds are of vital importance for pharmaceuticals and even for agrochemicals. Several methods for their synthesis have been developed throughout the last decades. One of these methods generates chiral compounds starting from achiral ones using enantioselective catalysis.

Most enantioselctive catalysts described so far in the literature are Homogeneous Catalysts that contain chiral ligands that induce chirality. However, there are also enantioselective heterogeneous powder catalyst where the catalytic active surface is modified by chiral compounds. Examples are tartrate modified Activated Base Metal Catalysts or cinchona modified supported precious metal catalysts (see also A. Baiker, H.-U. Blaser in Handbook of Heterogeneous Catalysis, Vol. 5 (Eds.: G. Ertl, H. Knötzinger, J. Weitkamp), VCH, Weinheim, 1997, 2422-2436).

For high enantiomeric excess and high catalytic activity the reaction conditions, the chiral modifier, and the supported Precious Metal Powder Catalyst have to be optimised. Evonik has managed to develop a new Pt/Al2O3 catalyst (catASium F214) that gives very high activity and excellent enantiomeric excess after modification with cinchona alkaloids.This catalytic system has been used by Solvias AG (EXTERNAL LINK) in the synthesis of various chiral alcohols.

For previous work with conventional catalyst technology see:

• P. Herold, A.F. Indolese, M. Studer, H. P. Jalett, U. Siegrist, H.-U. Blaser, Tetrahedron 2000, 56, 6497-6499.
• M. Studer, S. Burkhardt, A. F. Indolese, H.-U. Blaser, Chem. Commun. 2000, 1327-1328.
• H. U. Blaser, H. P. Jalett, W. Lottenbach, M. Studer, J. Am. Chem. Soc. 2000, 122, 12675-12682.
• M. Studer, H.-U. Blaser, C. Exner, Adv. Synth. Catal. 2003, 345, 45-65.

The main advantage of this catalyst, which is expected to give high ee and activity with the whole range of activated ketones mentioned below is that the tedious pretreatment with hydrogen at 400°C is no longer necessary and it exhibits unprecedented activity. This new catalyst was developed in a collaboration with Solvias AG (EXTERNAL LINK).

catASium F214 is one of the rare examples where a heterogeneous catalyst is used after chiral modification in a commercial enantioselective hydrogenation process.