81213-76-5

Upstream product

• 1456785-17-3 3-amino-3-(1-naphthyl)-1-phenylprop-2-en-1-one 
• 66-77-3 1-naphthaldehyde 
• 16736-86-0 1-(naphthalen-1-yl)-3-phenylprop-2-yn-1-one 
• 90-14-2 1-Iodonaphthalene 
• 199620-14-9 chromium⁽⁰⁾ hexacarbonyl 
• 536-74-3 phenylacetylene 
• 19350-73-3 4-methyl-N'-(naphthalen-1-ylmethylene)benzenesulfonohydrazide 

Relevant academic research and scientific papers

Sunlight-promoted Direct Irradiation of N-centred Anion: The Photocatalyst-free Synthesis of Pyrazoles in Water

A practical method through sunlight mediated annulation of α,β-unsaturated hydrazones has been developed for the synthesis of pyrazole. Based on the analysis of UV-Vis absorption of the substrate, the reaction was designed to avoid the use of external photocatalysis and proceeds via direct irradiation of N-centred anion by sunlight. The key features of this reaction include operational simplicity, readily available reagents, and amenability to gram-scale synthesis. (Figure presented.).

Phosphine- and copper-free palladium catalyzed one-pot four-component carbonylation reaction for the synthesis of isoxazoles and pyrazoles

The palladium catalyzed one-pot synthesis of isoxazoles and pyrazoles from aryl iodides, terminal alkynes, chromium hexacarbonyl and hydroxylamine hydrochloride or aqueous hydrazine solution is described. The Sonogashira carbonylative coupling intermediate was trapped in situ by hydroxylamine hydrochloride or aqueous hydrazine to deliver isoxazoles or pyrazoles, respectively, in high yields. This efficient method proceeds at atmospheric pressure and moderate temperature and does not require the use of copper, phosphine ligands or gaseous carbon monoxide.

Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine

The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.

Copper on iron promoted one-pot synthesis of β-aminoenones and 3,5-disubstituted pyrazoles

The reaction of hydroximoyl chlorides with acetylenes in the presence of a copper on iron bimetallic system leads to β-aminoenones via reductive ring opening of isoxazole intermediates. The valuable β-aminoenone building blocks can be isolated or transformed into pyrazoles with the addition of hydrazine in a straightforward one-pot procedure.

A complementary approach to 3,5-substituted pyrazoles with tosylhydrazones and terminal alkynes mediated by TfOH

A complementary method for the preparation of 3,5-substituted pyrazoles in moderate to high yields has been explored via TfOH-induced addition of tosylhydrazones to the terminal alkynes. This acid-induced addition procedure might be an operationally safe alternative compared to typical 1,3-dipolar cycloaddition as there is no involvement of diazo compounds.