1400575-44-1

Upstream product

• 288-13-1 NH-pyrazole 
• 149457-45-4 4-(2-bromophenylethynyl)anisole 
• 64-17-5 ethanol 
• 1174271-10-3 C₂₃H₂₀N₂O₃S 

Relevant academic research and scientific papers

Silver triflate-palladium chloride cooperative catalysis in a tandem reaction for the synthesis of H-pyrazolo [5,1-α]isoquinolines

A tandem reaction of N'-(2-alkynylbenzylidene) hydrazone with alcohol in the presence of oxygen co-catalyzed by silver triflate and palladium chloride under mild conditions is reported, providing H-pyrazolo [5,1-α] isoquinolines in good yields. During the transformation, isoquinolinium-2-yl amide was the key intermediate via a silver(I)-catalyzed 6-endo cyclization of N'-(2-alkynylbenzyli- dene)hydrazone. The presence of a palladium catalyst and molecular oxygen promoted the oxidation of the alcohol to the aldehyde or ketone. Subsequent nucleophilic attack of the in situ generated enolate to isoquinolinium-2-yl amide, intramolecular condensation, and aromatization afforded the H-pyrazolo- [5,1-α]isoquinolines. The easily available starting materials, good substrate generality, mild reaction conditions, and experimental ease should make this method attractive for further library construction.

Route to pyrazolo[5,1-a]isoquinolines via a copper-catalyzed tandem reaction of 2-alkynylbromobenzene with pyrazole

A copper-catalyzed tandem reaction of 2-alkynylbromobenzene and pyrazole is described that provides a facile route to pyrazolo[5,1-a]isoquinolines in good yields. During the reaction process, copper(I)-catalyzed hydroamination and C-H activation are involved.