A DDQ-mediated tandem reaction of 1,3-diarylpropenes and β-enaminoesters/4-aminocoumarins is disclosed. It involves oxidative coupling, intramolecular annulation and dehydro-aromatization reaction, which provides an efficient and mild method for the synthesis of polysubstituted and fused pyridines under metal-free conditions. Results and DiscussionInitially, β-enaminoester 1 a and 1,3-diphenylpropene 2 a were chosen as model substrates. The reaction was

The tandem reaction of enaminones with 1,3‐diarylpropenes mediated by 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) is reported, which involves the oxidative coupling and the intramolecular cyclization reactions. It provides a convenient, efficient and metal‐free method for the synthesis of 3‐allylated chromones and quinolone with potential biological activities.

An efficient tandem oxidative annulation for the synthesis of 2,2‐disubstituted 2,3‐dihydroquinazolin‐4(1H)‐ones via DDQ‐mediated dual cross‐dehydrogenative‐coupling (CDC) reactions is described. This transformation proceeds from easily available o‐aminobenzamides and 1,3‐diarylpropenes under mild conditions, and the corresponding products are obtained in moderate to excellent yields.

An oxidative annulation for the synthesis of 2,4-diarylquinolines from o-allylanilines is disclosed that uses recyclable reagent Chloranil­ as the oxidant. The corresponding products are obtained in moderate to excellent yields. Furthermore, a one-pot access to 2,4-di­aryl­quinolines from easily available anilines and 1,3-diarylpropenes is described as a highly atom-efficient protocol that involves oxidative coupling, rearrangement, and oxidative annulation.