Redox Induced Tunable Functionalization of Picolylamines on Selective Ru‐Platform

Abstract

Redox induced ligand centered reactivity has garnered significant attention in recent times. In this context, the present article described intermolecular oxygenation, dehydrogenation and C−N bond cleavage processes of structurally robust picolylamine derivatives (HL) on selective {Ru(acac)2} metal platform encompassing electron rich acac (=acetylacetonate) co‐ligand. The diverse functionalization of {Ru(acac)2} coordinated β‐ketoiminate embedded picolylamines under basic condition included (i) oxygenation of methylene (Cα) position of picolyl fragment (−CH2−NH−→−CO−NH−), (ii) dehydrogenation of phenyl substituted Cα (−CH−NH−→−C=N−) and (iii) C−N bond cleavage of the picolinoyl moiety to yield picolinate (−CO−N−−→−CO−O−). Besides structural, spectroscopic (mass, 1H/13C−NMR, EPR, UV‐vis.) and electrochemical authentication of the products, correlation of the reactivity pattern was addressed via transition state (TS) calculations. Theoretical results supported the consideration of a common dianionic intermediate to address the aforementioned reactivities. The pertinent question of intramolecular cyclization versus intermolecular oxygenation of picolylamine on simple switching from {Ru(Cl)(H)(CO)(PPh3)3} (earlier work[4a]) metal fragment to {Ru(acac)2} (present report) was also elaborated by TS calculation.