A general route to pyridine-modified salicylaldehydes via Suzuki coupling

Recent applications of the Suzuki–Miyaura cross-coupling reaction in organic synthesis

“…133 The PdCl 2 (dppf)-and Pd(PPh 3 ) 4 -catalysed reactions of 4-pyridylboronic acid with the corresponding bromides gave 68, which can furnish pyridine-substituted salicylaldehydes on further functional group transformations. 134 The reaction of carboxybenzeneboronic acid with heteroaryl bromides and chlorides gave the heteroaryl benzoic acids 69 in moderate to good yields. 135 Jones et al have developed a simple and general method for the synthesis of the substituted pyrazine systems 70 based on the SM cross-coupling reaction of 2-amino-3-benzoyl-5-bromopyrazine with arylboronic acids (it is interesting to note that the pyrazine unit is present in a luminescent chromophore, coelenterazine, and other marine natural products).…”

Enhanced activity of enantioselective (salen)Mn(III) epoxidation catalysts through supramolecular complexation

“…The (salen)Mn complex 2 with pendant pyridyl groups was obtained from the corresponding ligand [19] and Mn(OAc) 2 following published procedures [20]. Formation of a manganese-free version of complex 1 can be conveniently monitored by 1 H NMR studies which showed the significant upfield shift (∼4 ppm) of the resonance for the 2,6-pyridyl protons of the Schiff base ligand (R,R)-(−)-N,N -bis(3-tert-butyl-5-(4-pyridyl)-salicylidene)-1,2-diaminocyclohexane (3) upon addition of one equivalent of ZnTPP.…”

Palladium/tetraphosphine catalyzed suzuki cross‐coupling of heteroarylboronic acids with aryl halides

“…Two dialkylbiphenylphosphino ligands with 1-3% Pd 2 (dba) 3 are also efficient catalysts for the coupling of pyridineboronic acids with aryl halides [8,9]. Dppf as ligand gave satisfactory results for the arylation of thiophene, benzofuran and pyridineboronic acids [10][11][12][13][14]. A palladium complex with a di(norbornyl)phosphine and a 2-phenylpyridine ligand catalyses the arylation of 3-furan-and 3-thiopheneboronic acid derivatives using 5 mol % catalyst [15].…”