The main contributions in the field of first-row transition-metal-catalyzed (base-metal-catalyzed) carbonylative transformations have been summarized and discussed. The contents have been divided according to the electrophiles applied, followed by the different types of nucleophiles. Their reaction mechanisms and applications have been emphatically discussed.

First-Row Transition-Metal-Catalyzed Carbonylative Transformations of Carbon Electrophiles.

Ein neues interdisziplinares Forschungsgebiet ist die Biometallorganische Chemie; sie befast sich mit der Einfuhrung von metallorganischen Fragmenten in Biomolekule (siehe z. B. Struktur rechts). Die „klassischen” α-Aminosaure- und Peptidliganden haben sich dabei als besonders vielseitig erwiesen und eroffnen unter anderem einen Zugang zu stereochemisch interessanten Verbindungen. α-Aminosauren und Peptide konnen durch metallorganische Verbindungen synthetisiert, markiert, stabilisiert oder aktiviert werden.

Biometallorganische Chemie – Übergangsmetallkomplexe mit α‐Aminosäuren und Peptiden

New synthetic route to N-acyl-α-amino acids via amidocarbonylation by means of homogeneous binary catalyst systems

Gluconobacter oxydans DSM 2343 (ATCC 621H)catalyzes the oxidation of glucose to gluconic acid and subsequently to 5-keto-D-gluconic acid (5-KGA), a precursor of the industrially important L-(+)-tartaric acid. To further increase 5-KGA production in G. oxydans, the mutant strain MF1 was used. In this strain the membrane-bound gluconate-2-dehydrogenase activity, responsible for formation of the undesired by-product 2-keto-D-gluconic acid, is disrupted. Therefore, high amounts of 5-KGA accumulate in the culture medium. G. oxydans MF1 was equipped with plasmids allowing the overexpression of the membrane-bound enzymes involved in 5-KGA formation. Overexpression was confirmed on the transcript and enzymatic level. Furthermore, the resulting strains overproducing the membrane-bound glucose dehydrogenase showed an increased gluconic acid formation, whereas the overproduction of gluconate-5-dehydrogenase resulted in an increase in 5-KGA of up to 230 mM. Therefore, these newly developed recombinant strains provide a basis for further improving the biotransformation process for 5-KGA production.

Modification of the membrane-bound glucose oxidation system in Gluconobacter oxydans significantly increases gluconate and 5-keto-D-gluconic acid accumulation.

Germana Campari

Papers

Some aspects of the catalytic synthesis of N-acyl-α-aminoacids by carbonylation of aldehydes in the presence of amides