Synthesis Of Fused Polycyclic Molecules Based On Tandem Cycloisomerization Strategies

Tandem reaction means that for a particular organic transformation,the reactant components can react continuously in two or more individual steps in the same reaction environment to form the final product.Compared with traditional step-wise synthetic methods,tandem reactions have many advantages,such as high efficiency,convenience,atom economy and resource saving.Thus,these types of reactions are frequently applied in the synthesis of diversity molecules with complexity and also,in the synthesis of fused polycyclic compounds.Our group have developed several novel reactions based on the tandem cycloisomerization strategy.Based on these results,the following contents are mainly elaborated in this paper.(1)Recent advances in the synthesis of multivariate cyclic compounds from functionalized alkenes/alkynes via tandem cyclization reactions were briefly introduced.In addition,the synthesis of nitrogen-containing heterocyclic compounds based on Catellani reactions were summarized.(2)A new method for the synthesis of fluorescent benzo[b]fluorenones by cycloisomerization reactions of 1,5-enynes was developed.This reaction could efficiently construct fuse tetracyclic rigid skeletons under mild conditions and simple operations.(3)We developed palladium-catalyzed remoting C-H bond functionalization reactions to form series of medium-sized quinary polyheterocycles that were containing 8-membered ring structures.The structures of the obtained products were confirmed by X-ray diffraction analysis.(4)The experimental section and characterizations of all new compounds.