65349-21-5Relevant academic research and scientific papers
Rhodium-Catalyzed Cascade Annulative Coupling of 3,5-Diarylisoxazoles with Alkynes
Noguchi, Teppei,Nishii, Yuji,Miura, Masahiro
, p. 258 - 270 (2019/01/04)
A rhodium-catalyzed cascade annulative coupling of 3,5-diarylisoxazoles with three equivalents of an alkyne proceeds smoothly in the presence of a Cu(II) oxidant, where the sequential construction of isoquinoline and naphtho[1,8- bc ]pyran frameworks connected by a biaryl linkage is achieved by a single operation. Most of the obtained polycyclic compounds exhibit visible fluorescence in both the solution and the solid state. The hexaphenylated isoquinoline-naphthopyran conjugate (R = Ph) as a representative product shows a green emission which can be turned off by making an isoquinolinium salt with an acid. The emission is also reversibly turned on by treatment with a base.
Phosphine- and copper-free palladium catalyzed one-pot four-component carbonylation reaction for the synthesis of isoxazoles and pyrazoles
Iranpoor, Nasser,Firouzabadi, Habib,Etemadi-Davan, Elham
supporting information, p. 837 - 840 (2016/02/05)
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
Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
, p. 2049 - 2058 (2014/04/03)
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.
