02194nas a2200265   4500008004100000022001400041245011500055210006900170260000800239300001400247490000800261520130100269653001001570653001801580653002501598653002101623653000901644100002101653700002501674700002301699700002401722700002901746700002301775856013001798       2024                        eng d  a1011-372X00aZrO2 supported Cu nanoparticles for sonogashira and ullmann coupling reactions under palladium-free conditions0 aZrO2 supported Cu nanoparticles for sonogashira and ullmann coup  cJUN  a3078-30900 v1543 a<p>
	Cu nanoparticles supported on ZrO2 (CuNPs@ZrO2) were synthesized using a one-step co-precipitation process, and their application in C-C coupling reactions was investigated. The catalyst was characterized using XRD, XPS, SEM, TEM, and TGA techniques. The prepared catalyst was used for the Sonogashira cross-coupling reactions of aryl bromides with phenyl-acetylene in the presence of K2CO3 in DMF at 110 degrees C, which resulted in substituted alkynes with good to excellent yields. The protocol was also extended for the Ullmann coupling reactions of aryl iodides under similar reaction conditions, yielding the desired products with good to excellent yields without homo-coupling. Interestingly, unlike other copper catalysts, the present catalyst worked under air and did not require an inert atmosphere to prevent alkyne. This catalytic system is versatile, tolerant, and significantly cheaper than the ``traditional'' Pd-catalyzed Sonogashira cross-coupling of terminal alkynes with aryl halides. The catalyst could be reused for five catalytic cycles with no significant change in the product yield. All of these characteristics make our prepared CuNPs@ZrO2 catalyst quite suitable for the gram-scale synthesis of biaryls and alkynes, with a simple workup.{GRAPHIACAL ABSTRACT</p>
10aCuNPs10aRecyclability10aSonogashira coupling10aUllmann coupling10aZrO21 aPatil, Seema, P.1 aRajmane, Archana, S.1 aJadhav, Sanjay, N.1 aRajmane, Vijaya, S.1 aRode, Chandrashekhar, V.1 aKumbhar, Arjun, S.  uhttps://library.ncl.res.in/content/zro2-supported-cu-nanoparticles-sonogashira-and-ullmann-coupling-reactions-under-palladium