Facile preparation of N-tert-butyl amides under heat-, metal- and acid-free conditions by using tert-butyl nitrite (TBN) as a practical carbon source

tert-Butyl nitrite (TBN) is a nontoxic substance that has frequently been used as a source of nitrogen, oxygen, or nitric oxide (NO), but not as a carbon source in chemical transformations. Here, for the first time to the best of our knowledge, we introduced TBN as a source of carbon (tert-butyl group) for the synthesis of highly valuable N-tert-butyl amides from nitriles and water under very mild conditions.

De Novo Protocol for the Construction of Benzo[a]fluorenes via Nitrile/Alkene Activation

Unprecedented chemo- and regioselective synthesis of benzo[a]fluorenes and naphthamide-substituted benzo[a]fluorenes were constructed from the reaction of (E)-2-aroyl-3-(2-(arylalkynes/alkenes)aryl)acrylonitrile scaffolds under metal-free conditions via the activation of nitriles and alkenes, respectively. A tentative reaction mechanism was proposed for this homofunctionalization of nitriles. Control experiments showed that the reaction proceeds via selective nitrile or alkene protonation, depending upon the substrates. Additionally, we demonstrated an alternative expeditious route for the synthesis of disubstituted benzo[a]fluorenes in the presence of TfOH alone.

Lewis Acid Catalyzed Atom-Economic Synthesis of C2-Substituted Indoles from o-Amido Alkynols

Herein we have disclosed a Zn(OTf)₂ catalyzed synthesis of C2-alkyl substituted indole derivatives via unprecedented carbonyl group migration from o-amido alkynols. The key features of this protocol involve N,O-carbonyl group migration, broad substrate scope with varied functionality tolerance, moderate to good yields, and 100% atom economy. The crossover experiments proved that the migration is happening via an intramolecular pathway.