Palladium-catalyzed Cross-coupling Of Terminal Alkenes To Synthesize Conjugated Dienes Via C-H Activation Pathway

Palladium catalysis functionalization of C-H bonds is a powerful method for generating chemical bonds.The introduction section of this thesis summarized the reported examples for the formation of C-C bond,C-N bond,C-O bond,C-S bond,and C-X bond in the C-H activation field.Compounds containing conjugated-diene structures are widely used in materials,natural products,pharmaceuticals and organic synthesis.Direct cross-coupling of terminal alkenes via C-H bond activation pathway meets the needs of green chemistry.Palladium-catalyzed C-H functionalizations of terminal alkenes is challenging due to the low reactivity of the substrates.Using Pd（OAc）₂ as catalysts in this paper,we have examined several ligands,oxidants,solvent,additives.Finally,the dehydrogenation cross-coupling of acrylates or aryl olefins has been achieved by using 6-hydroxyl-4,4’-ditert-butyl-2,2’-bipyridin as ligands and Ag₂CO₃ as the oxidant.We have got up to 90%yield of products by using acrylic esters as the substrates,and got up to 73%yield of dienes by using aryl olefins as the substrates.This reaction may be utilized as a method for the synthesis conjugated dienes.