Silver-Catalyzed Nitration/Annulation of α-Alkynyl Arylols toward 3-Nitrated Benzofurans

Tian-Shu Zhang, Lei Yang, Pei-Jun Cai,* Shu-Jiang Tu, Bo Jiang*

A new silver-catalyzed nitration/annulation of α-alkynyl arylols was reported by using tert-butyl nitrite (TBN) as a NO₂ radical precursor, from which a set of 3-nitrated benzofurans were synthesized with moderate to good yields. This transformation initiated by an in situ generated NO₂ radical proceeds efficiently under mild and neutral redox conditions, which provides a new pathway toward 3-nitrobenzofuran framework via catalytic difunctionalization of internal alkynes.

Chem. Asian. J. 2019, 14(23), 4383-4388, DOI: 10.1002/asia.201901400