KCS

Heterocycles including pyridine are one of the most widely studied classes. Pyridine and its derivatives are easily found in natural products and of great importance in synthetic chemistry, pharmaceutical and agrochemical research. Therefore, numerous synthetic methods have been reported to form functionalized pyridines. Palladium catalyzed cross coupling reaction is one of the most convenient and versatile method for the preparation of trisubstituted pyridines from polyhalogenated pyridines. Therefore, regioselective Suzuki-Miyaura reactions on 3,5- and 4,6-dibromo-2-tosyloxypyridine have been studied. Herein, we reports the optimized conditions allow for facile access to 3,5- and 4,6-diaryl-2-tosyloxypyridines in yields of 8 to 99%. Further functionalization of the tosylate group in the diarylpyridine derivatives obtained was accomplished for the synthesis of novel and biologically relevant trisubstituted pyridines. The formal synthesis of ficuseptine, a bioactive alkaloid, also has been achieved via palladium-catalyzed cross-coupling reaction of 3,5-dibromo-2-tosyloxypyridine in 5 steps with 48% overall yield from 3,5-dibromo-2-hydroxypyridine.