The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《ONO pincer palladium (II) complexes featuring furoylhydrazone ligands: Synthesis, characterization and catalytic activity towards Suzuki-Miyaura coupling reaction》. Authors are Qian, Hengyu; Yu, Shuyan; Song, Liping; Zhang, Tongyan; Yin, Zhigang; Zhao, Feng; Yang, Jiale; Wang, Caihong.The article about the compound:2-Furoic hydrazidecas:3326-71-4,SMILESS:O=C(C1=CC=CO1)NN).Synthetic Route of C5H6N2O2. Through the article, more information about this compound (cas:3326-71-4) is conveyed.
Four new palladium pincer complexes I (R = H, 3-OMe, 3-OEt, 5-Cl) incorporating ONO type furoylhydrazone ligands have been prepared in good yields. These palladium complexes were structurally characterized by elemental anal., IR, 1H- and 13C-NMR spectra. X-ray single crystal analyses of Pd1-Pd4 revealed that the metal center adopted a slightly distorted square planar geometry in which the hydrazone bound the metal ion via the phenolic-O, azomethine-N and imidolate-O atoms. Using these ONO pincer complexes as catalyst, excellent yields of biaryls could be obtained for coupling of arylboronic acids with aryl bromides at a low catalyst loading (0.01 mol%).
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Reference:
Benzisoxazole – Wikipedia,
Benzisoxazole – an overview | ScienceDirect Topics