| This paper has two chapters:Chapter 1: Background IntroductionFirstly, we discuss the future application prospect of a-ferrocenylmethylpyrazoles. And we summarize the limitations of the existing synthetic methods of a-ferrocenylmethylpyrazoles, which make us feel the urgency of developing a new synthetic method. Furthermore, we briefly describe the synthesis of 2-substituted-1, 3-diones. At last, we put our attentions on the cleavage of carbon - nitrogen bonds in a-aminoalkylferrocenes, which is generally achieved via nucleophilic substitutions with complete retention of configuration.Chapter 2: Reaction of a-aminoalkylferrocenes with AllenonesIn this chapter, we briefly reviewed the reaction of allenones with amines.Based on their superior reactivity, we design the reaction of α-aminoalkylferrocenes and allenones to synthesize α-ferrocenylmethylpyrazoles in one pot. With the optimal reaction conditions in hand, we evaluated the scope of the reaction. We found that our reaction had broad substrates scope and excellent functional groups tolerance. The presence of electron-rich groups, eletron-deficient groups, alkyl or heterocycle did not block the reaction. What’s more, our reaction can run easily at mild reaction conditions without any difficulties in operation. Especially when we use optically active a-aminoalkylferrocenes, the products can be obtained with complete retention of configuration and excellent retention of enantiopurity. This is of great value in the preparation of chiral ligands. |
