Introduction New methods are facilitating the total chemical synthesis of proteins. In particular, the chemical ligation of synthetic peptides provides a convergent route to proteins. Currently, the most common ligation method is “native chemical ligation” [1]. In native chemical ligation, the thiolate of an N-terminal cysteine residue of one peptide attacks the C-terminal thioester of a second...

The traditional Staudinger/aza-Wittig reaction represents one of the most powerful tools for imine formation. However, this multistep procedure, sacrificial phosphine has to be used, resulting in difficulties purification process and waste disposal at same time. Here, we report a redox-neutral azide–alcohol imination methodology enabled by base-metal nickel PN3 pincer catalyst. one-step, waste-...

A new synthetic approach for the production of carbon nanomaterials (CNM) decorated with organophosphorus moieties is presented. Three different triphenylphosphine oxide (TPPO) derivatives were used to decorate oxidized multiwalled carbon nanotubes (ox-MWCNTs) and graphene platelets (GPs). The TPPOs chosen bear functional groups able to react with the CNMs by Tour reaction (an amino group), nit...

A fast and efficient protocol for the synthesis of N,N'-disubstituted urea derivatives from alkyl halides and primary or secondary amines has been developed. The synthetic pathway combines nucleophilic substitutions and a Staudinger-aza-Wittig reaction in the presence of polymer-bound diphenylphosphine under 14 bar of CO2 pressure and has been performed in a one-pot two-step process. The protoc...

A novel method for radioisotope-free photoaffinity labeling was developed, in which a bifunctional ligand is connected to a target protein by activation of a photoreactive group, such as an aromatic azido or 3-trifluoromethyl-3H-diazirin-3-yl group, and identification of the ligated product is achieved by anchoring of a detectable tag through the Staudinger-Bertozzi reaction with an alkyl azido...

The [2 + 2] cycloadditions of thioketenes and imines are named as thio-Staudinger cycloadditions. The diastereoselectivity in thio-Staudinger cycloaddtions of alkyl/alkenyl/aryl-substituted thioketenes is rationalized. The steric effects of the thioketenes play an extremely important role in deciding the diastereoselectivity (cis/trans selectivity) through controlling exo- and endo-attack and s...

The fi rst az.ide-contain ing sugar, a glycosyl azide. was reponed in 1930 by Bertho. j Since that lime various methods have been developed for the introduction of azides at d ifferent positions of sugars. A survey of available methods is given in Section 16.2. Unlillhc lale I 970s, azidcs contai ned in carbohydrate deri vatives were simply used as accessible syn-thons [or amities because of th...

Krystyna Lesiak and Wojciech J. Stec Polish Academy of Sciences, Centre of Molecular and Macromolecular Studies, 90-362 Lodz, Boczna 5, Poland Z. Naturforsch. 33b, 782-785 (1978); received March 28, 1978 1,3,2-Oxazaphospholidines, (—)Ephedrine, Thioanilides, Thioesters, Stereochemistry Both isomers of 2-anilido-3,4-dimethyl-5-phenyl-l,3,2-oxazaphospholidine-2-thiones (2 a and 2 b) derived from ...