Details

Autor(en) / Beteiligte

• Devi, Lalita
• Sharma, Gaurav
• Kant, Ruchir
• Shukla, Sanjeev K
• Rastogi, Namrata

Titel

Regioselective synthesis of functionalized pyrazole-chalcones via a base mediated reaction of diazo compounds with pyrylium salts

Ist Teil von

• Organic & biomolecular chemistry, 2021-05, Vol.19 (18), p.4132-4136

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A base-mediated reaction of triaryl/alkyl pyrylium tetrafluoroborate salts with α-diazo-phosphonates, sulfones and trifluoromethyl compounds affords the corresponding functionalized pyrazole-chalcones as 5-P-5 and 3-P-3 tautomeric mixture. The reaction proceeds through an initial nucleophilic addition of diazo substrates to pyrylium salts followed by a base-mediated pyrylium ring-opening and intramolecular 1,5-cyclization to afford formal 1,3-dipolar cycloaddition products. The products underwent a Nazarov-type cyclization upon hydride reduction followed by acidic-workup, furnishing the corresponding indenyl-pyrazoles in high yields.