The Reaction Properties Of Aza-heterocycle Compounds Derived From Indole And Pyrrole

Aza-heterocyclic compounds are widely distributed in nature, and play an vital role in the life system. Most drugs are aza-heterocyclic Compounds. Therefore, the synthesis of these kinds of compounds have a very important significance. In this thesis, I focused on the transformations of aza-heterocyclic compounds. My research work can be divided into three parts.Part Ⅰ:we have developed an interesting asymmetric substitution process of O-Boc-protected Morita-Baylis-Hillman adducts with various pyrrole and indole derivatives in the presence of (DHQD)2PYR, affording the corresponding products in good to high yields (up to99%yield) and moderate to high ee values (up to92%ee and96%ee) under mild conditions,which is applicable to a wide range of substrates from MBH adducts. This new asymmetric catalytic system can overcome the drawback in the asymmetric substitution of Morita-Baylis-Hillman carbonates with methyl pyrrole-2-carboxylate.Part Ⅱ:we have developed an efficient PTC-promoted cascade reaction of pyrrole-2-carbaldehyde substituted Morita-Baylis-Hillman adducts, leading to pyrrolo[1,2-a]azepin-7(6H)-one skeletons in moderate to good yields. This cascade reaction proceeds with high stereoselectivity through a C-N bond cleavage along with a new C-N bond formation as well as an intramolecular aldol reaction. Meanwhile, A novel Palladium-mediated intramolecular Heck reaction from indole-containing MBH adducts has also been developed which using tetrabutylammonium acetate as a base.Part III:Firstly, We have developed an efficient synthetic approach to bisindolylalkynes. With bisindolylalkynes as substrates, we have found a novel gold-catalysed intramolecular annulation. Using cationic gold catalyst [Me4tBuXPhosAu]SbF6as the best catalyst, the reaction has a wide substrate scope. To be noted, we found that by adjusting the electrical properties of the ligands, reactions were proceeded smoothly with various substituents on the alkyne moiety. Then, we also investigated asymmetric catalysis of this reaction, a variety of types of chiral phosphine ligand were tested, and the highest ee value is40%. A further study of asymmetric catalysis and reaction mechanism is ongoing in our group.