Direct arylation and Suzuki-Miyaura coupling of imidazo[1,2-a]pyridines catalyzed by (SIPr)Pd(allyl)Cl complex under microwave-irradiation

Abstract

<jats:p>A short and practical arylation of imidazo[1,2-a]pyridine and imidazole derivatives with aryl halides or aryl boronic acids as coupling partners was successfully carried out using phosphine-free (SIPr)Pd(allyl)Cl as the catalyst [SIPr: (N,N’-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene)] ((SIPr)Pd(allyl)Cl complex). 3,6-disubstituted imidazo[1,2-a]pyridine and 5-substituted imidazole compounds were obtained in good to excellent yields in only 1h under microwave-assisted C-H arylation and Suzuki-Miyaura coupling reaction conditions.</jats:p>

Sustainable protocols for direct C–H bond arylation of (hetero)arenes

“…Examples of microwave-assisted C3 arylation on the imidazolyl[1,2-a]pyridine moiety with non-commercially available Pd catalysts, such as preformed palladium acetate complex bearing phosphine and N-heterocyclic carbene ligands 352 and (SIPr)Pd(allyl)Cl complex [SIPr: (N,N′-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene)] 373 were also reported. As can be easily foreseen, although on one hand in all these studies the use of microwaves offered the possibility of reducing the energy requirements, on the other the choice of noncommercially available catalysts, which are often the result of quite long and tedious synthetic procedures, may have a negative impact on the overall cost of these direct C-H bond arylation.…”

Unlocking the Potential of Deep Eutectic Solvents for C–H Activation and Cross-Coupling Reactions: A Review

“…On the other hand, cross-coupling reactions can join a wide range of organic molecules, including aryl halides, vinyl halides, aryl triflates, boronic acids or boronates, alkynes, and alkyl halides, to form a new molecule with a carbon–carbon bond. There are numerous publications, such as articles and reviews, that discuss C–H activation and cross-coupling reactions [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. These reactions have been extensively studied and widely used in organic synthesis, making them a popular research topic in chemistry.…”

Synthesis, Anticancer Activities and Molecular Docking Studies of a Novel Class of 2-Phenyl-5,6,7,8-tetrahydroimidazo [1,2-b]pyridazine Derivatives Bearing Sulfonamides

“…Heterocycles are an important class of chemical compounds present in a wide variety of drugs, vitamins, natural products and biomolecules, as well as biologically active molecules [4][5][6][7]. Accordingly, our group has for many years been developing new methods towards the synthesis and functionalization of various heterocyclic systems [8][9][10][11][12][13].…”