Study On Palladium-catalyzed Cross-coupling Reaction Of Allyl Carboxylates

Transition metal-catalyzed cross-coupling reaction have emerged as a powerful tool for the efficient construction of carbon-carbon and carbon-heteroatom bonds,hence,have become the most attractive and versatile methods in organic synthesis chemistry.Transition metals especially palladium are respected by synthetic chemists because of high efficiency and high selectivity in organic reactions.Palladium-catalyzed cross-coupling reactions have shifted from basic research to practical aspects gradually,such as functional materials,natural products and pharmaceutical intermediates.Chemical researchers have synthesized a wide variety of organic molecules via palladium-catalyzed coupling reaction of allyl carboxylates.In this paper,two palladium-catalyzed cross-coupling reactions based on allyl carboxylates were developed:In Chapter 1,the reaction characteristics of allyl carboxylates in synthetic chemistry,palladium-catalyzed coupling reaction based on the allylic position of allyl carboxylates and palladium-catalyzed coupling reaction of carbon-carbon double bonds of allyl carboxylates were introduced.In Chapter 2,palladium-catalyzed coupling reaction of allyl alkynoates with isocyanides is described.We have achieved the cross-coupling of allyl alkynoates with isocyanides as a series of 1,4-enyne-3-ones were obtained.This approach shows advantages of mild reaction conditions and excellent functional group compatibility.The mechanism shows that the reaction is through the activation of C-O bond of allyl alkynoates by metal palladium,and then the intramolecular decarboxylation to form alkynyl allyl palladium intermediates,followed by cross-coupling reaction with isonitriles.In Chapter 3,palladium-catalyzed tandem reaction of allyl carboxylates,norbornenes and diboronates is described.Combining with the preliminary work of our group,we developed a three-component coupling reaction of allyl alkanoates,norbornenes and diboronates in the condition of Pd（PPh₃）₄ as catalyse,Zn（OTf）₂ as Lewis acid and 1-propanol as solvent which allows efficient construction of a C（sp³）-C（sp³）bond and a C（sp³）-B bond in a single reaction.The reaction have good chemoselectivity and regioselectivity,and good substrate suitability.