- Turkish Journal of Chemistry
- Vol: 39 Issue: 6
- Synthesis, characterization, and microwave-assisted catalytic activity in Heck, Suzuki, Sonogashira,...
Synthesis, characterization, and microwave-assisted catalytic activity in Heck, Suzuki, Sonogashira, and Buchwald--Hartwig cross-coupling reactions of novel benzimidazole salts bearing N-phthalimidoethyl and benzyl moieties
Authors : Hasan Küçükbay, Ülkü Yilmaz, Kemal Yavuz, Nesrin Buğday
Pages : 1265-1278
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Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :Five novel benzimidazole salts (\textbf{1}--\textbf{5}) having N-phthalimidoethyl and 4-substituted benzyl were synthesized and identified by $^{1}$H NMR, $^{13}$C NMR, and IR spectroscopic methods and microanalysis. A mixture of the benzimidazole salts (\textbf{1}--\textbf{5}), Pd(OAc)$_{2}$, and K$_{2}$CO$_{3}$ in DMF-H$_{2}$O catalyzed, in high yield, the Suzuki--Miyaura and the Heck--Mizoroki cross-coupling reactions assisted by microwave irradiation in 5 min. The novel benzimidazole salts (\textbf{1}--\textbf{5}), Pd(OAc)$_{2}$, Cs$_{2}$CO$_{3}$, PEG, and Cu nanoparticles catalyzed, in high yield, the Sonogashira coupling reaction promoted by microwave irradiation in 10 min. The same benzimidazole salts (\textbf{1}--\textbf{5}), Pd(OAc)$_{2}$, Cs$_{2}$CO$_{3}$, and TBAB catalyzed, in moderate or low yield, the Buchwald--Hartwig reaction assisted by microwave irradiation in 60 min. The efficiency of the catalyst system in these four reactions was discussed as well as the electron-releasing and withdrawing substituent effects on the benzimidazole ligands.Keywords : Heck--Mizoroki coupling, Suzuki--Miyaura coupling, Sonogashira coupling, Buchwald--Hartwig coupling, benzimidazole derivatives, catalyzes, N-heterocyclic carbene, microwave