Delgado-Collado Juan Manuel, Fernández de Córdova Francisco José, Palma Pilar, Cámpora Juan, Rodríguez-Delgado Antonio
Instituto de Investigaciones Químicas, CSIC-Universidad de Sevilla, Av. Américo Vespucio, 49, Sevilla 41092, Spain.
Inorg Chem. 2025 Aug 4;64(30):15760-15773. doi: 10.1021/acs.inorgchem.5c02587. Epub 2025 Jul 24.
The reversible storage and release of hydride equivalents remains a central challenge in the design of biomimetic redox systems. Cationic 2,6-bis(imino)pyridine organoaluminum complexes [(4-R-BIP)AlR] (where = H; ' = Me, 1a; ' = Et, 1b; = Bn; ' = Me, 1c) and their neutral 2,6-bis(imino)-4-R-dihydropyridinate counterparts [(4-R-HBIP)AlR] 2a-c are presented as chemically reversible hydride exchangers. Interconversion between these systems is achieved through strong reducing agents such as M[HBEt] (where = Li; Na) or LiAlH, while powerful electrophiles like B(CF) or cationic trityl salts PhC enable the reverse transformation, with the latter providing complete selectivity. Overall, this reversible hydride exchange mirrors natural NAD(P)H/NADP cofactor system. These findings establish a new platform for ligand-centered hydride shuttling, where the metal fragment acts as a passive modulator─inverting the traditional roles assigned to metal and ligand.
氢化物等价物的可逆存储和释放仍然是仿生氧化还原系统设计中的核心挑战。阳离子型2,6-双（亚氨基）吡啶有机铝配合物[(4-R-BIP)AlR]（其中 = H；' = Me，1a；' = Et，1b； = Bn；' = Me，1c）及其中性的2,6-双（亚氨基）-4-R-二氢吡啶酸盐类似物[(4-R-HBIP)AlR] 2a-c被作为化学可逆氢化物交换剂提出。这些体系之间的相互转化通过强还原剂如M[HBEt]（其中 = Li；Na）或LiAlH实现，而像B(CF)或阳离子型三苯基盐PhC这样的强亲电试剂则能实现逆向转化，后者具有完全的选择性。总体而言，这种可逆氢化物交换反映了天然的NAD(P)H/NADP辅因子系统。这些发现建立了一个以配体为中心的氢化物穿梭新平台，其中金属片段充当被动调节剂——颠倒了传统上赋予金属和配体的角色。
