Synthesis of Carbene-Stabilized PNPN Fragments and Their Carbene-Dependent Redox Properties
作者:Etienne A. LaPierre、Brian O. Patrick、Ian Manners
DOI:10.1021/jacs.4c00148
日期:2024.3.6
to 4CAAC. The nature of the stabilizing carbene also influences the redox properties of the compound, with 4CAAC undergoing potassium-mediated reduction to the closed-shell P–P bonded dimer K252, which upon treatment with Kryptofix-2,2,2 converts to the transient radical anion [Kcrypt][5], the formal one-electron reduction product of 4CAAC. In contrast, 4NHC undergoes reversible one-electron oxidation
在此,我们报道了卡宾稳定的1,3-二氮杂-2,4-二磷丁烯CAAC Me PNPNCAAC Me 4 CAAC (CAAC Me = 1-[2,6-双(异丙基)苯基]-3,3,5 ,5-四甲基-2-吡咯烷亚基)和IPrPNPNIPr 4 NHC (IPr = 1,3-双(2,6-二异丙基苯基)-咪唑-2-亚基)。两个系统中的键合均由离域极性共价 π 系统定义,其中4 NHC相对于4 CAAC表现出增强的共轭性。稳定卡宾的性质也会影响化合物的氧化还原性质, 4 CAAC会经历钾介导的还原,生成闭壳 P-P 键合二聚体K 2 5 2 ,经过 Kryptofix-2,2,2 处理后会发生转化到瞬态自由基阴离子 [K crypt ][ 5 ], 4 CAAC的正式单电子还原产物。相反, 4 NHC经历可逆的单电子氧化,形成稳定的自由基阳离子[ 6 NHC ][SbF 6 ]。对两种自由基物质的计算