Cyclometalated Ruthenium Catalyst Enables Selective Oxidation of <i>N</i>-Substituted Tetrahydroquinolines to Lactams
Monuranjan Konwar, Tapashi Das, Animesh Das
Abstract
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 study demonstrates that the high-valent Ru(VI)- cis -dioxo species plays an important role in controlling selectivity.
Topics & Concepts
ChemistryCatalysisMethyleneRutheniumSelectivityCombinatorial chemistryMedicinal chemistryStereochemistryOrganic chemistryCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and CatalysisSynthetic Organic Chemistry Methods