Mimicking transition metals in borrowing hydrogen from alcohols

Abstract

Borrowing hydrogen from alcohol, storing it on the catalyst and subsequent transfer of the hydrogen from catalyst to an in situ generated imine is the hallmark of a transition metal...

Phenalenyl Radical: Smallest Polycyclic Odd Alternant Hydrocarbon Present in the Graphene Sheet

“…These special properties of phenalenyl-based molecules originate from their unique molecular orbital construction (presence of NBMO). Such diverse potential of the phenalenyl-based molecules in material science encouraged Mandal and co-workers ,− to strategize a new direction of applications using phenalenyl-based molecules toward designing catalysts for various organic transformations. Such design enables the use of phenalenyl-based molecules in mimicking metals during various catalytic transformations.…”

“…From 2012 onward, such molecules were further utilized in designing efficient catalysts for various organic transformations, taking advantage of the energetically accessible nonbonding molecular orbital (NBMO) in their cationic states. It was anticipated that the empty NBMO of the cationic phenalenyl molecule could behave as an electron acceptor, which inspired Mandal and co-workers ,− to design various catalytic organic transformations using such molecules. This section will discuss the development of catalytic strategies by these molecules.…”

“… − –The phenalenyl-based molecules have demonstrated tremendous potential in designing bistable, spintronic, optoelectronic, and cathode materials due to their unique bonding and electronic properties in their radical state. − The synthesis and bonding properties of phenalenyl-based radicals and their potential as intriguing materials have already been described in detail in a few excellent reviews earlier. − Until 2012, this field of phenalenyl-based radicals was limited to its synthesis, theoretical study, and potential as various valuable materials. Since 2012, the phenalenyl-based molecules were explored toward a completely different field of catalysis which spans from hydroamination, , ring-opening, , olefin hydrosilylation, C–C cross coupling, − electrocatalysis, borrowing hydrogen-mediated catalysis, , etc. The strategies for developing catalytic methods utilized the empty NBMO of the phenalenyl molecules for its ability to accept electron(s) without compromising their stability.…”

Recent advances in C/N-alkylation with alcohols through hydride transfer strategies

“…While preparing this manuscript, Mandal and coworkers reported the successful N -alkylation of anilines with both primary aliphatic and aromatic alcohols employing a redox-potent phenylenyl-based catalyst (Scheme 79a). 88 PYL's reversible dearomatization/aromatization operates hydrogen storing on its skeleton in different pathways involving radical, cation, and anion intermediates. TEMPO deterred reaction progress and verified the radical intermediate participation in the mentioned coupling system.…”

N‐Alkylation of α‐Amino Esters and Amides through Hydrogen Borrowing

“…Subsequent imine formation and reduction by the hydrogen stored on the catalyst gives the alkylated amine in a one pot process. Ir [7] and Ru [8] complexes are well known to catalyse this transformation, and more recently Ni, [9] Cu, [10] Co, [11] Mn, [12] Fe, [13] W [14] and organocatalytic [15] systems have been developed.…”