Synthesis of 2‑Amino-3-hydroxy‑3<i>H</i>‑indoles via Palladium-Catalyzed One-Pot Reaction of Isonitriles, Oxygen, and <i>N</i>‑Tosylhydrazones Derived from 2‑Acylanilines

A cyanide-free one-pot procedure was developed to access 2-amino-3-hydroxy-3<i>H</i>-indoles, which involved: (1) <i>in situ</i> formation of ketenimines by the reaction of <i>N</i>′-(1-(2-amino­phenyl)­ethylidene)-<i>p</i>-tosyl­hydrazones with isonitriles; (2) the intramolecular nucleophilic attack of ketenimines by the amino in phenyl furnishing the ring closure leading to 2-aminoindoles; (3) the oxidation of 2-aminoindoles by O₂ leading to 2-amino-3-hydroxy-3<i>H</i>-indoles. This strategy represents not only a key compliment to the sporadic synthetic methods toward 2-amino-3-hydroxy-3<i>H</i>-indoles but also progress in <i>N-</i>tosylhydrazone, isonitrile, and ketenimine chemistry

Synthesis of 2‑Amino-3-hydroxy‑3<i>H</i>‑indoles via Palladium-Catalyzed One-Pot Reaction of Isonitriles, Oxygen, and <i>N</i>‑Tosylhydrazones Derived from 2‑Acylanilines

A cyanide-free one-pot procedure was developed to access 2-amino-3-hydroxy-3<i>H</i>-indoles, which involved: (1) <i>in situ</i> formation of ketenimines by the reaction of <i>N</i>′-(1-(2-amino­phenyl)­ethylidene)-<i>p</i>-tosyl­hydrazones with isonitriles; (2) the intramolecular nucleophilic attack of ketenimines by the amino in phenyl furnishing the ring closure leading to 2-aminoindoles; (3) the oxidation of 2-aminoindoles by O₂ leading to 2-amino-3-hydroxy-3<i>H</i>-indoles. This strategy represents not only a key compliment to the sporadic synthetic methods toward 2-amino-3-hydroxy-3<i>H</i>-indoles but also progress in <i>N-</i>tosylhydrazone, isonitrile, and ketenimine chemistry

Copper-Catalyzed <i>N</i>‑Cyanation of Sulfoximines by AIBN

The direct copper-catalyzed <i>N</i>-cyanation of sulfoximines was achieved by using AIBN as a safe cyanide source. It represents a simple and environmentally benign procedure for the construction of the N–CN bond. Furthermore, some <i>sec</i>-amines can also be tolerated well under this procedure

Diethylene Glycol Serving as Ethyne Equivalent: A Sustainable Approach toward 2,3-Disubstituted Furan

In the presence of <i>tert</i>-butyl peroxide (TBHP), the copper-catalyzed annulation of 1,3-dicarbonyl compound with diethylene glycol was developed leading to 2,3-disubstituted furan. Diethylene glycol serves as a cheap and environmentally friendly equivalent of ethyne, with the release of H₂O and alcohol as clean wastes. The procedure involves a sequential <i>O</i>- and <i>C</i>- functionalization of β-ketoester by diethylene glycol