A series of 1,2- and 2,3-fused quinazolinones have been synthesized in good to excellent yields through gold-catalyzed selective hydroarylations of alkynyl quinazolinone-tethered pyrroles. The studies revealed that 1,2-fused quinazolinones were obtained through a 1,3-rearrangement and sequential 6- exo-trig cyclization of N1-alkynyl quinazolinone-tethered pyrroles, while N3-alkynyl quinazolinone-tethered pyrroles went through 6- exo-dig or 7- endo-dig cyclizations directly to afford 2,3-fused quinazolinones. The fused quinazolinones could be prepared at gram scale in three steps from commercial ortho-aminobenzamide.

A silver-catalyzed selective 8-endo-dig cyclization of C2-alkynyl quinazolinones was developed to prepare a series of novel quinazolinone-fused eight-membered N,O-heterocycles in good-to-excellent yields under mild reaction conditions.

An efficient and metal-free double CÀH bond amination of N-aryl enamines using isobutyl nitrite (IBN) has been developed. This method enables the preparation of functionalized quinoxalines in good to excellent yields and tolerates a variety of N-aryl enamines with diverse functional substituents. Mechanistic studies revealed the presence of a key b-imino oxime ester intermediate. A quinoxaline derivative could be prepared from bcarbonyl ester in one-pot sequence on a gram scale. Finally, two important quinoxaline scaffolds were easily prepared in moderate yields over two steps.