Single Step Synthesis of Non-symmetric Azoarenes Using Buchwald-Hartwig Amination.

Aromatic azo compounds stand as a highly sought-after class of substances owing to their extensive array of applications across various fields. Despite their significance, their synthesis often presents challenges, requiring either multistep reactions or being restricted to specific substrate types. In this study, we are showing the universality and mechanistic aspects of a one-step approach for synthesis of nonsymmetrical azoarenes via the Buchwald-Hartwig amination reaction of (pseudo)haloaromatics with arylhydrazines, conducted in the presence of atmospheric oxygen.

Synthesis of ()-3-[amino(phenyl)methylidene]-1,3-dihydro-2-indol-2-ones using an Eschenmoser coupling reaction.

A highly modular method for the synthesis of ()-3-[amino(phenyl/methyl)methylidene]-1,3-dihydro-2-indol-2-ones starting from easily available 3-bromooxindoles or (2-oxoindolin-3-yl)triflate and thioacetamides or thiobenzamides is described. A series of 49 compounds, several of which have previously been shown to possess significant tyrosin kinase inhibiting activity, was prepared in yields varying mostly from 70 to 97% and always surpassing those obtained by other published methods. The method includes an Eschenmoser coupling reaction, which is very feasible (even without using a thiophile except tertiary amides) and scalable.