Catalytic Asymmetric Hydrogenation in the Manufacture of d-Biotin and Dextromethorphan

Two enantiomerically pure products, (+)-biotin and dextromethorphan, have been chosen to illustrate the acquisition, development, and implementation of the catalytic asymmetric hydrogenation technology at Lonza Fine Chemicals. Taking advantage of the recently developed Ciba-Geigy ferrocenyl-type phosphine ligands, processes for the stereoselective hydrogenation of a C=C- and a C=N bond, respectively, have been developed and successfully scaled up

Biotransformations for Fine Chemical Production

Biotechnology has become an indispensable tool for the production of fine chemicals. The choice of route, chemical or biotechnological, for the manufacture of a given fine chemical is crucial. In general terms, biotechnology is the method of choice for large molecules with a high degree of functionalisation and multiple stereocentres. Most of LONZA's biotechnological bioprocesses for the production of fine chemicals are whole cell processes using microorganisms which form very specific enzymes. Process improvement at LONZA is discussed in this paper on three levels: upstream processing, biotransformation/biosynthesis, and downsteam processing

Synthesis, Structure, and Electrochemistry of Fischer Alkoxy- and Aminocarbene Complexes of Tungsten: The Use of DFT To Predict and Understand Oxidation and Reduction Potentials

Reactions of Fischer alkoxycarbene complexes [W(CO)5{C(OEt)Ar}], Ar = thienyl (1) or furyl (2), with ethylene diamine lead to the formation of two different reaction products: an aminolysis product (5 or 6) where the ethoxy substituent of the carbene ligand is replaced by the ethylene diamine moiety, as well as a chelated product where aminolysis and substitution of one carbonyl ligand had taken place, yielding 7 or 8. Aminolysis of 1 and 2 with cyclohexyl amine (CHA) produced the aminocarbene complexes 3 (Ar = thienyl) and 4 (Ar = furyl). Complexes 1-8 are electrochemically investigated by means of cyclic voltammetry. The relative shifts in the oxidation and reduction potentials are discussed and related to density functional theory (DFT) calculated energies. DFT calculations further show that the oxidation center is located on the metal and the carbonyl groups, while the reduction center is localized on the carbene moiety and is strongly influenced by the electronic properties of its substituents. Crystal structures of 1-4, 6 and 8 are reported.Norwegian Supercomputing Program (NOTUR) through a grant of computer time (Grant No. NN4654K) (J.C.), the South African National Research Foundation (J.C.) and the Central Research Fund of the University of the Free State, Bloemfontein (J.C.), and the University of Pretoria (M.L. and P.H.v.R.).http://pubs.acs.org/journal/orgnd7hb201