Studies On Novel Copper-mediated C-N, C-O Bond Forming Reactions

Pyrrole rings constitute an important class of heterocyclic compounds, which represent not only are useful intermediates in the synthesis of natural products as well as in heterocyclic chemistry but also key structural units in compounds that exhibit remarkable pharmacological activities. They have also found broad applications in the field of material science. Many compounds with pyrrole ring have exhibited physiological activities and interesting biologic properties. As a consequence, much attention has been paid to the development of efficient methodologies for the preparation of polysubstituted pyrroles.An efficient copper-catalyzed double alkenylation of amides or carbamate with (1Z, 3Z)-1, 4-diiodo-1, 3-dienes derivatives is reported for the first time. The reactions proceed to afford di- or trisubstituted N-acylpyrroles in good to excellent yields using CuI as the catalyst, rac-trans-N,N-dimethylcyclohexane-1, 2-diamine as the ligand, and Cs₂CO₃ as the base.14 desired products were synthesized with the yield from 32% to 95%. ¹H and ¹³C NMR spectra of all compounds and crystallographic data of one compound is available.Lactones have drawn considerable attention for they are useful intermediates for organic synthesis and key structural unit of some natural compounds. A new synthetic methodology for the formation of six - membered or seven - membered lactone from zirconacycles was also described. Six-membered or seven-membered lactone could be obtained selectively by changing the reaction temperature. 6 desired products were synthesized with moderate yield.