Chiral 1,5-disubstituted 1,2,3-triazoles - versatile tools for foldamers and peptidomimetic applications.

1,4- and 1,5-Disubstituted triazole amino acid monomers have gained increasing interest among peptidic foldamers, as they are easily prepared via Cu- and Ru-catalyzed click reactions, with the potential for side chain variation. While the latter is key to their applicability, the synthesis and structural properties of the chiral mono- or disubstituted triazole amino acids have only been partially addressed. We here present the synthesis of all eight possible chiral derivatives of a triazole monomer prepared via a ruthenium-catalyzed azide alkyne cycloaddition (RuAAC).

Ruthenium-Catalyzed Azide Alkyne Cycloaddition Reaction: Scope, Mechanism, and Applications.

The ruthenium-catalyzed azide alkyne cycloaddition (RuAAC) affords 1,5-disubstituted 1,2,3-triazoles in one step and complements the more established copper-catalyzed reaction providing the 1,4-isomer. The RuAAC reaction has quickly found its way into the organic chemistry toolbox and found applications in many different areas, such as medicinal chemistry, polymer synthesis, organocatalysis, supramolecular chemistry, and the construction of electronic devices. This Review discusses the mechanism, scope, and applications of the RuAAC reaction, covering the literature from the last 10 years.

Selective cleavage of 3,5-bis-(trifluoromethyl)benzylcarbamate by SmI2-Et3N-H2O.

A novel electron poor protection group for amines has been developed. It undergoes rapid cleavage by SmI2-Et3N-H2O and its orthogonality towards the regular benzyl carbamate group (CBz) under reductive or transfer hydrogenolytic conditions is reported.