Metal- and Catalyst-Free, Formal [4 + 1] Annulation via Tandem C=O/C=S Functionalization: One-Pot Access to 3,5-Disubstituted/Annulated Isothiazoles
Gaurav Shukla, Abhijeet Srivastava and Maya Shankar Singh*
*Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India, Email: mssinghbhu.ac.in
G. Shukla, A. Srivastava, M. S. Singh, Org. Lett., 2016, 18, 2451-2454.
DOI: 10.1021/acs.orglett.6b00997 (free Supporting Information)
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An operationally simple and user-friendly synthesis of 3,5-disubstituted/annulated isothiazoles from β-ketodithioesters/β-ketothioamides and NH4OAc via C=O/C=S bond functionalization under metal- and catalyst-free conditions. The carbon-economic [4 + 1] annulation relies on a sequential imine formation/cyclization/aerial oxidation cascade forming consecutive C-N and S-N bonds in one pot.
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