Chiral Ferrocenylphosphines Catalyzed [3+2] Cycloaddition Reaction And The Construction Of Azaspiro[4.4]Nonanes

Chiral phosphine organocatalysis used in asymmetric reactions have made great progress and attracted broad attention of researchers in recent years.All kinds of phosphines perform well with rapid reaction rate,high stereoselectivity and low catalyst loading.But there were several disadvantages such as expensive,easily oxidized,lower stability than tertiary amine etc for the present studied phosphines.Due to these problems,we designed and synthesized a series of cheap and stable chiral ferrocenylphosphines,which were used to catalyze highly enantioselective[3+2]cycloaddition reaction.Furthermore,the[3+2]cycloaddition reaction is considered to be one of the most efficient methods towards the construction of functional five-membered rings.So,it will lead to important significance and potential applications to construct azaspiro[4.4]nonanes by the[3+2]cycloaddition reaction.This dissertation consisted of two parts.The first one was the design,synthesis and applications of ferrocenylphosphines.The second one was focused on the construction of azaspiro[4.4]nonanes by[3+2]cycloaddition reaction.In part one,firstly,the research progress of chiral phosphine organocatalysis and ferrocenylphosphines were briefly reviewed.Then,on the basis of our previous works,“Lewis Base”and“Br?nsted acid”were combined with ferrocene to successfully design and produce a series of chiral bifunctional ferrocenylphosphines LB1-LB8.Finally,LB1-LB8were applied to promote asymmetric[3+2]cycloaddition reaction as catalysts.Among them,LB5 presented good catalytic performance.Then,we immediately examined the influence of different tempreture,catalyst loading and solvents,which showed that the optimized conditions were10 mol%LB5,25 ^oC,in toluene.Under the optimized conditions,the influence on yield and ee value with different substrates was evaluated.The experimental results showed that LB5 has good stability and afforded the corresponding bicyclic imides with 84–99%ee and 67–99%yield.Finally,we have proposed a plausible reaction transition states.In part two,firstly,some synthetic methods of spiroheterocycles were simply summarized.Then,the azaspiro[4.4]nonanes were synthesized by[3+2]cycloaddition reaction with high yields?50-96%yield?and diastereoselectivities under moderate conditions?chloroform,PPh₃,room tempreture?.And a plausible mechanism for this reaction was proposed in the paper.