A simple and convenient method was developed for the preparation of hindered tertiary amines via direct reductive amination of ketones with secondary aryl amines, using trichlorosilane as reducing agent and tetramethylethylenediamine (TMEDA) as organic Lewis base activator. A broad range of ketones were reacted with N-methylaniline to afford the corresponding tertiary amine products in high yie...

Valine dehydrogenase was purified to homogeneity from the crude extracts of Streptomyces aureofaciens. The molecular weight of the native enzyme was 116,000 by equilibrium ultracentrifugation and 118,000 by size exclusion high-performance liquid chromatography. The enzyme was composed of four subunits with molecular weights of 29,000. The isoelectric point was 5.1. The enzyme required NAD+ as a...

The large scale industrial manufacture of the nasal decongestant pseudoephedrine is typically carried out by the reductive amination of l-phenylacetylcarbinol (l-PAC), which in turn is produced via the biotransformation of benzaldehyde using yeast. In recent years there has been increasing legislative control of the supply of pseudoephedrine due to it being diverted for the clandestine producti...

Disaccharides tagged with p-aminobenzoic acid (ABA) were separated by capillary electrophoresis (CE) and analyzed on-line with negative ion electrospray ionization tandem mass spectrometry (ESI/MS/MS). The formation of glycosylamine instead of reductive amination was selected as the derivatization reaction. In negative ion ESI, the glycosylamine approach provides more information on linkage and...

A short synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and a formal synthesis of australine are described. In both cases, D-fructose is employed as the starting material and converted into a protected methyl 6-deoxy-6-iodo-furanoside. Zinc-mediated fragmentation produces an unsaturated ketone which serves as a key building block for both syntheses. Ozonolysis, reductive amination with be...

BACKGROUND Transaminases have become a key tool in biocatalysis to introduce the amine functionality into a range of molecules like prochiral α-ketoacids and ketones. However, due to the necessity of shifting the equilibrium towards the product side (depending on the amine donor) an efficient amination system may require three enzymes. So far, this well-established transformation has mainly bee...

We have developed a general strategy for the synthesis of 2,5-syn disubstituted pyrrolidines that is based on the multi-faceted reactivity of the sulfone moiety and a 5-endo-trig cyclisation. This methodology was applied to the synthesis of indolizidine alkaloid monomorine I. Two factors were key to the success of this endeavour; the first was the choice of nitrogen protecting group whilst the ...