A new radical-mediated intramolecular arene C(sp2)-H amidation of 3-phenylpropanamides or [1,1'-biphenyl]-2-carboxamides was developed to prepare a series of 3,4-dihydro-2(1H)-quinolinone and phenanthridone derivatives in moderate to excellent yields (33-94%). Spirolactams could also be obtained using this protocol.
Cyclometalated Ruthenium Catalyst Enables Selective Oxidation of <i>N</i>-Substituted Tetrahydroquinolines to Lactams
作者:Monuranjan Konwar、Tapashi Das、Animesh Das
DOI:10.1021/acs.orglett.3c04263
日期:2024.2.16
Herein, we report an unusual α-methylene oxidation of N-substituted tetrahydroquinoline to lactams using the cyclometalated Ru(II)-complex as a catalyst. Cyclic-α-methylene C–H bonds are selectively oxidized under the reaction conditions even in the presence of α-methyl or reactive α-methylene C–H bonds. This methodology is also useful in the late-stage functionalization of pharmaceuticals. Mechanistic
Abstract A simple protocol has been proposed for the visible light-induced aromatic amidation reaction to afford 3,4-dihydroquinolin-2(1H)-ones. The amidation proceeded smoothly without any photocatalyst at room temperature, and the desired products were obtained in 46–72% yields.
A Rh/Pd/Cu catalyst system led to an efficient synthesis of dihydroquinolinones in one-pot, two operations. The reaction features the first triple metal-catalyzed transformations in one reaction vessel, without any intermediate workup. The conjugate-addition/amidation/amidation reaction sequence is highly modular, divergent, and practical.