A new set of Pd(II) O^N^O pincer complexes is synthesized and characterized. Further, the solid-state molecular structures of the complexes have been well authenticated by single-crystal XRD studies. The catalytic efficacy of complexes has been explored towards N-alkylation of benzamides/sulfonamides using aromatic primary alcohols through borrowing hydrogen strategy.

The development of green, sustainable, and atom-economical procedure for the construction of amides via C-N bond formation is a high priority in synthetic organic community. In this research article, we demonstrate a simple and an efficient catalytic protocol for N-alkylation of benzamides/sulfonamides using aromatic primary alcohols as coupling partners through borrowing hydrogen (BH) strategy by employing newly constructed palladium (II) O^N^O pincer complexes. All the palladium complexes are characterized by analytical and spectral methods (FT-IR, NMR, and HRMS). Further, the solid-state molecular structures of the complexes have been well authenticated by single-crystal XRD studies. The present N-alkylation protocol is facile, worked in low catalyst loading (0.5 mol%), and furnishes the desired N-alkyl amides with excellent yields up to 92%. In this methodology, the reaction proceeds via the formation of intermediates such as aldehyde and (E)-N-benzylidenebenzamide with a release of water as ecological by-product. The control experiments and plausible mechanistic investigations suggested that the coupling reaction was initially proceeds via dehydrogenation of alcohol and generate the alkylated products through hydrogen auto-transfer. A large-scale synthesis of N-(4-methoxybenzyl)benzamide proves the effectiveness of the Pd (II) pincer catalysts.