Study On The Synthesis Of Poly-substituted Pyrroles Via Hypervalent Iodine Reagents

This thesis consists of three parts. In the first part, the recent progress in the synthetic studies on pyrroles is briefly introduced. The second and third parts deal with our studies on the synthesis of pyrroles which feature the use of hypervalent iodine (Ⅲ) reagents. Our research includes (1) The synthesis of polysubstituted pyrroles via PhI(OAc)2-mediated oxidative coupling of enamine esters (or ketones). We found that in the presence of catalytic amount of BF3·Et2O, enamine esters (or ketones) could be oxidized by PhI(OAc)2, forming homo-coupling products, the symmetric poly-substituted pyrroles. It is also possible for the cross-coupling to take place under the reaction conditions. (2) BF3·Et2O-catalyzed reactions between phenyliodonium ylides and enamine esters. Phenyliodonium ylides derived from 1,3-dicarbonyl compounds could react with enamine esters in the presence of BF3·Et2O to generate poly-substituted pyrroles. As the results of our research, two new protocols for the synthesis of poly-substituted pyrroles were developed.