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
NESRİN BUĞDAY

DOI

10.3906/kim-1505-34

Abstract

Five novel benzimidazole salts (1-5) 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 (1-5), 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 (1-5), 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 (1-5), 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

First Page

1265

Last Page

1278

Recommended Citation

KÜÇÜKBAY, HASAN; YILMAZ, ÜLKÜ; YAVUZ, KEMAL; and BUĞDAY, NESRİN (2015) "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," Turkish Journal of Chemistry: Vol. 39: No. 6, Article 12. https://doi.org/10.3906/kim-1505-34
Available at: https://journals.tubitak.gov.tr/chem/vol39/iss6/12