2-Pyridone Directed CuII-Catalyzed General Method of C(sp2)-H Activation for C-S, C-Se and C-N Cross Coupling: Ease Access to Aryl Thioethers, Selenide Ethers and Sulfonamides, and DFT Study

Authors: Pati, Tanmay K.; Molla, Sabir Ali; Ghosh, Narendra Nath; Kundu, Mrinalkanti(TCGLS Member); Ajarul, Sk; Maity, Pradip ; Khamrai, Uttam(TCGLS Member); Maiti, Dilip K.

Abstract: N-substituted 2-pyridones as an N,O-directing group for selective C(sp²)-H activated thiolation, selenylation and sulfonamidation of ortho C-H bonds of benzamides was demonstrated . This method utilizes a cost-effective Cu(II)-salt catalyst instead of precious metal catalysts, achieving high yields, including gram-scale synthesis and excellent functional group tolerance. This protocol applied to access 30 different compounds with high yields, demonstrating thiolation of fluorine-substituted benzamides as well. D. functional theory (DFT) calculations support the mechanism, including acetate-supported concerted metalation deprotonation (CMD) steps and the unique role of DMSO solvent. The facile synthesis of pharmaceutically important sulfonamides and other compounds highlights the method′s potential in chem. and medicinal chem.