Design And Synthesis Of A New Type Of Monophosphine Ligand And Study On The Gold-Catalyzed Cycloisomerization Of 1,6-Enynes

Asymmetric catalysis is the most efficient way to obtain chiral products, because it can achieve the growth of the chirality. Chiral ligands play a very important role in asymmetric catalysis. Therefore, the design and synthesis of a new type chiral ligand is the important subject in the field of asymmetric catalysis. This dissertation mainly consists of two parts.In the first part, in asymmetric catalysis, ligands play a important role in controling enantioselectivity. Heterocycle ligands have the advantage of diverse frameworks and easy to modify. Therefore, we designed a series of chiral monophosphine ligands which were based on the framework of indole. At last, after many attempts we successfully synthesized a series of new ligands. Besides, we attempted to apply these ligands to asymmetric reaction.In the second part, with our continuous interesting in gold-catalyzed asymmetric reactions, we attempted to the gold-catalyzed asymmetric cycloisomerization of 1,6-enynes consisting of cation promoted rearrangement of alkylidenecyclobutane, leading to enantioenriched multifunctionalized tricyclic products. A series of chiral ligands and conditions were screened and up to 89% was obtainted, but in only 16% yield. To solve this problem we turned on changing the substrates, unfortunately, we found out that the yields of most reaction were generally low, and the effort to rise the yield is still in progress.