Highly Diastereoselective One-Pot Synthesis of 4,5-Dihydrofuro[2,3-b]azocin-6-one Derivatives through Cyclization/[4+4] Annulation Reactions.

A variety of 4,5-dihydrofuro[2,3-b]azocin-6-one derivatives were expediently assembled through Au(I)-catalyzed cyclization and 2-(tert-butyl)-1,1,3,3-tetramethylguanidine (BTMG)-mediated [4+4] annulation reactions of enyne-amides and ynones. The reactions exhibit high efficiency with excellent regio- and diastereoselectivity. A broad spectrum of substrates was utilized. The products with an eight-membered ring might be useful in biological chemistry and medicinal science. Furthermore, the products could be facilely converted into various derivatives.

One-pot synthesis of 4-(imidazol-1-yl)indole derivatives through a sequential dearomatization and Ag-catalyzed cyclization/Cs2CO3-mediated addition/aromatization reaction.

A convenient one-pot assembly of 4-(imidazol-1-yl)indole derivatives from easily accessible o-alkynylanilines and imidazoles has been developed. The sequential dearomatization and Ag(I)-catalyzed cyclization/Cs2CO3-mediated conjugate addition/aromatization cascade reactions exhibit high efficiency and excellent selectivity. The combined use of a silver(I) salt and cesium carbonate is significant for facilitating this domino transformation. The 4-(imidazol-1-yl)indole products could be easily converted to the corresponding derivatives and might be valuable in biological chemistry and medicinal science.