Categories: Synthesis of N-Heterocycles > benzo-fused N-Heterocycles >
Synthesis of 2,3-dihydroquinolin-4-ones
A mild and efficient one-pot procedure starting from o-aminoacetophenones and aromatic aldehydes in the presence of silver(I) triflate provides various 2-aryl-2,3-dihydroquinolin-4(1H)-ones. This method has several advantages, such as the use of easily available starting materials, the efficiency of the catalyst, a simple operation, and tolerance of a wide range of functionality in the aldehydes.
R. P. Pandit, K. Sharma, Y R. Lee, Synthesis, 2015, 47, 3881-3890.
The use of zirconyl nitrate as a water-tolerant Lewis-acid catalyst enables a simple, green, and efficient intramolecular cyclization of o-aminochalcones to provide 2-aryl-2,3-dihydroquinolin-4(1H)-ones under mild reaction conditions with improved yields.
A. Gorepatil, P. Gorepatil, M. Gaikwad, D. Mhamane, A. Phadkule, V. Ingle, Synlett, 2018, 29, 235-237.
A convenient environmentally friendly method for the cyclization of 2-aminochalcones to 2-aryl-2,3-dihydroquinolin-4(1H)-ones on the surface of silica gel impregnated with indium(III) chloride under microwave irradiation without any solvent has been reported.
K. H. Kumar, D. Muralidharan, P. T. Perumal, Synthesis, 2004, 63-68.
Amino-substituted chalcones undergo a 1,7-hydride shift upon Lewis acid activation to form a zwitterionic iminium enolate, which collapses to dihydroquinoline-4-ones in high yields with an excellent diastereoselectivity.
G. Wicker, R. Schoch, J. Paradies, Org. Lett., 2021, 23, 3626-3630.