Bis‐benzimidazolium‐palladium system catalyzed Suzuki‐Miyaura coupling reaction of aryl bromides under mild conditions

Abstract

Bis-benzimidazolium salts were prepared successfully from commercially available and inexpensive o-phenylenediamine through a series of simple reactions. The bis-NHC-Pd complexes prepared in situ can catalyze Suzuki-Miyaura cross-coupling reaction under very mild conditions in aqueous media with excellent yields. The efficiency of this reaction is demonstrated by its compatibility with a range of functional groups. Di-ortho-substituted biaryls could be accomplished in 89-99% yields. Moreover, the rigorous exclusion of air or moisture is not required in these transformations.

An efficient class of bis-NHC salts: applications in Pd-catalyzed reactions under mild reaction conditions

“…Although both K 2 CO 3 and K 3 PO 4 $H 2 O showed excellent conversion yields (entries 9 and 10), K 3 PO 4 $H 2 O was selected for further studies according to our previous works. 6,9 Further studies demonstrated that the reaction could be completed even when only 0.5 mol% of Pd/1c was employed (entry 12), which was then used as our standard reaction condition for the substrate scope exploration.…”

Expanding the Chemical Space of Benzimidazole Dicationic Ionic Liquids

“…In addition, for BDILs, the majority of the attention has been paid by the organic chemistry community, with an emphasis on their role as reaction catalysts. BDILs have been used in many transformations spanning from Heck [84], Suzuki [85], Benzoin [86], and Kumada couplings [87] to desulfurization reactions [88], and esterifications [89]. Furthermore, by treating a DBIL with a strong base, a cyclic "dimer" can be formed, which is highly reactive toward air and can be used as an organic super-electron donor [90].…”

Palladium complexes derived from benzoylthiourea ligands: Synthesis, crystal structure, and catalytic application in Suzuki C–C coupling reactions

“…[27][28][29][30][31][32][33][34][35][36][37] Moreover, more amounts of catalyst or longer time may be required for catalytic conversions. [22,38,39] On the other hand, benzoylthiourea ligands are generally stable in air and moisture, and their catalytic properties can be easily controlled by changing the N-substitution. [34,37,40,41] Moreover, N-substituted benzoylthioureas are the organic compounds with donor atoms that provide a large number of bonding possibilities such as nitrogen, sulfur, and oxygen atoms.…”