Suzuki-miyaura cross-coupling reaction of dichloro-heteroaromatics: Synthesis of functionalized dinucleophilic fragments

Abstract

The Suzuki-Miyaura cross-coupling reaction has successfully been applied for the synthesis of 4,4'- [6-(diethylamino)-1,3,5-triazine-2,4-diyl]diphenol (4a), 4,4'-(pyrimidine-4,6-diyl)diphenol (4b), 4,4'-(pyridine-2,6-diyl)diphenol (4c). The reaction of 4,6-dichloro-N,N-diethyl-1,3,5-triazin-2-amine (1a), 4,6-dichloropyrimidine (1b) and 2,6-dichloropyridine (1c) with p-methoxyphenylboronic acid (2) in the presence of palladium catalyst followed by demethylation reaction furnished the desired products in good to excellent yields. To test the reactivity of these nucleophiles, the compound 4a was further reacted with cyanuric chloride to get trimeric fragment (5a). All the compounds were characterized by their physical, spectral (1H and 13C NMR and Mass) and microanalytical data. These dinucleophilic fragments (4a-4c) having triazine, pyrimidine and pyridine rings, respectively, are excellent future candidates for the construction of large functional hetero-atom bridged macrocycles for diverse applications in host-guest chemistry, supramolecular catalysis, self-assembly and other related fields of supramolecular chemistry in addition to their potential in medicinal chemistry.