Solution-phase synthesis of 2-cyano and 2-amido aziridinyl peptides

The effect of backbone flexibility on site-selective modification of macrocycles

The interplay of rotatable backbone torsions determines the ring-opening regioselectivity of electrophilic aziridines in macrocyclic peptide scaffolds.

Selective amination reactions of α-nitro aryl and heteroaryl enoates

Highly functionalized tetrasubstituted alkenes were obtained by an unexpected amination reaction promoted by ethyl nosyloxycarbamate on various α-nitro aryl and heteroaryl enoates. A nitrene is likely the aminating species responsible for the observed insertion reaction leading to (E)-β-amino α-nitro enoates as the major products, regardless of the substrate configuration. The compounds, bearing two nitrogenous functional groups in different oxidation states, can be regarded as interesting synthons. In contrast, aziridination was observed for α-nitro alkyl enoates or β-nitro allylic alcohols.

Synthesis and ring openings of cinnamate-derived N-unfunctionalised aziridines

tert-Butyl cinnamates are aziridinated with high trans-selectivity by an N–N ylide generated in situ from N-methylmorpholine and O-diphenylphosphinyl hydroxylamine. The resulting N-unfunctionalised aziridines are shown to be versatile synthetic building blocks that undergo highly selective ring-opening reactions with a wide range of nucleophiles.

One-pot highly stereoselective synthesis of cyano aziridines via the CuCl-catalyzed aminochlorination of α,β-unsaturated nitriles and intramolecular S(N) 2 substitution

An efficient one-pot system has been developed for the synthesis of cyano aziridine by using α,β-unsaturated nitriles as the alkene substrates and N,N-dichloro-p-toluenesulfonamide (4-TsNCl(2) ) as the nitrogen source. A good scope of alkene substrates was achieved for this reaction. The one-pot reaction, via aminohalogenation and intramolecular S(N) 2 substitution, was very convenient to carry out at room temperature without the protection of inert gases. Modest to good yields and excellent have been obtained. This method provides an easy route to the cyano aziridine. The structure of the resulting products has been unambiguously confirmed by X-ray structural analysis.