Class Of Natural Small-molecule Compounds Synthesized Methodology

This theis mainly focused on the methodology development for the synthesis of some natural product-like compounds.(1) As a privileged fragment,the 3-aminocoumarin core is found in many natural products and pharmaceuticals that exhibit remarkable biological activities.We have developed an efficient and facile route for the generation of 3-aminocoumarins via palladium-catalyzed amination reactions.The combination of Pd₂dba₃ and Xantphos shows high efficiency in the amination reactions of 3-bromo-4-sulfanylcouamrins, which generate the desired 3-amino-4-sulfanylcouamrins in good to excellent yields.(2) Carbon tetrabromide is discovered as an efficient catalyst in the one-pot reaction of aldehyde,1,3-cyclohexanedione,ethyl acetoacetate and ammonium acetate.The 4-substitude-1,4-dihydropyridine could be obtained in high yield.The advantages of this method include high efficiency,good substrate generality,mild reaction conditions,and experimental ease.(3) Arylidene dimalonate is an important intermediate in the synthesis of many natural products and has found many applications in industry.The first example for access to arylidene dimalonate is obtained via a tandem Knoevenagel-Michae addition reaction of sulfonimine.