作者:Taiga Karimata、Shinya Adachi、Masakatsu Shibasaki、Naoya Kumagai
DOI:10.1248/cpb.c22-00215
日期:2022.9.1
An iterative hydride reduction/oxidation process was promoted under ambient conditions by a quasi-planar iminium cation rigidified by two concatenated quinoline units. The iminium proton was fixed by hydrogen bonding from neighboring quinoline nitrogen atoms, rendering the imine highly susceptible to hydride reduction with weak reductants, e.g., 1,4-dihydropyridines. The thus-formed amine was readily oxidized by molecular oxygen to regenerate the quasi-planar iminium cation under ambient conditions. This process was exploited for catalytic oxidation of 1,4-dihydropyridines as well as 9,10-dihydroacridine to highlight an intriguing rigidity-driven catalysis.
在环境条件下,通过两个连接的喹啉单元固定准平面亚胺阳离子,促进氢化物还原/氧化过程的反复进行。亚胺质子通过氢键与相邻喹啉氮原子结合,使亚胺极易与弱还原剂(如1,4-二氢吡啶)发生氢化还原反应。由此形成的胺很容易被分子氧氧化,从而在环境条件下再生准平面亚胺阳离子。这一过程被用于1,4-二氢吡啶和9,10-二氢吖啶的催化氧化,以突出有趣的刚性驱动催化作用。