Applications of quinoxaline-bridged bis(benzimidazolium) salts as ligand sources for the palladium-catalyzed Suzuki and Heck cross-coupling reactions in an aqueous medium
JOURNAL OF THE CHINESE CHEMICAL SOCIETY, vol.69, no.11, pp.1937-1953, 2022 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 69 Issue: 11
- Publication Date: 2022
- Doi Number: 10.1002/jccs.202200304
- Journal Name: JOURNAL OF THE CHINESE CHEMICAL SOCIETY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, CAB Abstracts, Chemical Abstracts Core, INSPEC
- Page Numbers: pp.1937-1953
- Keywords: bis(benzimidazolium) salt, Heck coupling, N-heterocyclic carbene, palladium, quinoxaline, Suzuki coupling
- Inonu University Affiliated: Yes
Abstract
In the present work, quinoxaline-bridged bis(benzimidazolium) salts were prepared by the reaction of 2,3-bis(bromomethyl) quinoxaline and 1-substituted benzimidazole. The structures of the bis(benzimidazolium) salts were characterized by NMR, FT-IR, and elemental analysis techniques. Also, the photophysical properties of salts were investigated by UV-Vis absorption and fluorescence emission spectroscopy. Next, these quinoxaline bridged bis(benzimidazolium) salts were used as bidentate benzimidazol-2-ylidene ligand precursors in the palladium-catalyzed Suzuki-Miyaura and Mizoroki-Heck cross-couplings. These salts exhibited moderate-to-high activity in the palladium-catalyzed cross-coupling reactions.