Three simple methods for the synthesis of geminal triazides are described: Starting from 1) 3-oxocarboxylic acids, 2) iodomethyl ketones, or 3) terminal olefins, a range of triazidomethyl ketones can be constructed under mild oxidative reaction conditions by the use of IBX-SO3 K, a sulfonylated derivative of 2-iodoxybenzoic acid (IBX), and NaN3 as an azide source. This is the first report of representatives of this novel class of triazide compounds: Despite their high nitrogen content, the geminal triazides are easy to handle, even when preparative-scale syntheses are performed. (Caution: These procedures still require protective measures!) The triazides are now broadly available for further studies regarding their properties and reactivity. Furthermore, we show how the method can be used to provide α-azidoesters, which are potential building blocks for amino acids.

Geminal diazides constitute a rare class of compounds where only a limited number of methods are available for their synthesis. We present the reaction of 1,3-dicarbonyl compounds (as exemplified by malonates, 3-oxoesters, and 1,3-diketones) with molecular iodine and sodium azide in aqueous DMSO providing a general access to geminal diazides. A broad range of geminal diazides with various structural motifs including sterically demanding substituents and ordinary functional groups were synthesized, and it was shown that the diazidation of 1,3-dicarbonyls can be selectively achieved even in the presence of other 1,3-dicarbonyls with substituents at 2-position. Additionally, several diazides were studied regarding their thermal stability.

Cyclodepsipeptides of the enniation, PF1022 and verticilide families represent a diverse class of highly interesting natural products with respect to their manifold biological activities. However, until now, no practicable solid‐phase syntheses of these compounds have been accomplished, probably due to the problematic combination of N‐methyl amino acids and hydroxycarboxylic acids. We report herein an efficient synthesis of the anthelmintic PF1022A and its commercial analogue emodepside on Kaiser and Wang resins. Our protocol provides the basis for the solid‐phase synthesis of cyclodepsipeptide libraries with a high probability of anthelmintic, antibacterial or insecticidal activity.

A new chiral derivatizing agent for α-amino acids is described which leads to diastereomers that can be separated by reverse-phase HPLC with direct detection by a diode array detector. The main advantage of the presented procedure is the fact that an excess of the derivatizing reagent can be employed as the product exhibits an absorption maximum at 360 nm, while the reagent has its absorption maximum at 260 nm. Therefore, it is possible to suppress the reagent signal by a detection wavelength of 400 nm leading to an easy and general method for the enantioseparation of a mixture of DL-amino acids and the determination of the enantiomeric purity of α-amino acid as exemplified by 16 different α-amino acids.

It is shown how imidazolinones are reduced by trichlorosilane in a highly enantioselective fashion when treated with a novel Lewis base organocatalyst that is based on a 2,2'-bispyrrolidine core. Under mild reaction conditions and with low catalyst loading the hydrosilylation reaction provides a broad range of chiral imidazolidinones with various structural motifs including sterically demanding substituents, alkyls and aryls.