Studies On Palladium/Norbornene Synergistically Catalyzed Trisubstitution Of Arynes

1,2,3-Trisubstituted arenes are one kind of important frameworks in organic synthesis.They have been widely used in pharmaceuticals,agrochemicals,functional materials and so on.Traditionally,1,2,3-trisubstituted arenes can be assembled by either transition-metal catalyzed multi-step couplings or cycloaddition of unsaturated systems.However,these methods always suffer from lenthy and low-efficient routes,unavailable starting materials,incompatibility with rapid generation of diversity,and/or uncontrollable selectivity.In this thesis,by using readily available substrates,we have developed a new one-pot synthetic method for the construction of1,2,3-trisubstituted arenes,which has the remarkable advantages such as conciseness and suitability for rapid generation of diversity.(i)Based on palladium-norbornene cocatalysis,an one-pot four-component method for the assembly of 1,2,3-allyl-alkenyl-alkyl arenes has been developed.Through the optimization on the reaction conditions,the optimal condition of this reaction has been obtained.The investigation on the reaction scope reveals that this reaction can tolerate a large array of functional groups.Based on a series of experimental results,a possible mechanism has been proposed for the reaction.By the use of this method,polyfunctional arenes with three contiguous but different substituents can be accessed in an one-pot manner,thereafter showing its potentially broad application space.(ii)An one-pot four-component method for the assembly of1,2,3-allyl-alkenyl-aminyl arenes has been developed.After optimizing the conditions and expanding the substrates,the subsequent conversion reactions of the products were further studied have been performed supplying a foundation for futher use of this method in organic synthesis.