Gold-Catalyzed Synthesis of (Dihydro)quinolones by Cyclization of Benzaldehyde-Tethered Ynamides and Anilines

2-Quinolones represent a versatile class of compounds that are prevalent in natural and medicinally relevant molecules. Here we report a new approach to the selective formation of these structures. By gold catalysis, a range of benzaldehyde-tethered ynamides reacted with anilines, leading to 4-amino-3,4-dihydro-2-quinolones with high efficiency and excellent diastereoselectivity in dichloromethane. Interestingly, with methyl acetate as the solvent, the same reaction produced 3-aryl 2-quinolones as the major products. The use of a substoichiometric amount of the aniline could also promote this transformation.