有机硼烷与过氧自由基的反应是其用作大量自由基链式反应的自由基引发剂的关键,特别是在需要高立体选择性或区域选择性的低温下。虽然这些反应通常通过一致的均解取代 (S H 2) 机制进行,但带有可稳定四配位硼自由基“ate”复合物的基团的有机硼烷(例如儿茶酚硼烷)通过逐步添加/断裂顺序进行该反应,并用作有用的化学计量烷基自由基前体。在这里,我们表明,分别衍生自儿茶酚硼烷和二氨基萘硼烷的芳基硼酸酯和酰胺是有效的自由基捕获抗氧化剂(RTA)。机理研究表明,这是因为过氧自由基与硼加成产生的自由基“吃”络合物足够持久,可以在中断的 S H 2 反应中捕获另一个自由基。值得注意的是,这些有机硼烷作为自动氧化抑制剂的反应性被证明可以从简单的碳氢化合物转化为生物膜的磷脂,从而可以抑制铁死亡,这是由脂质自动氧化驱动的细胞死亡方式,与神经变性和其他主要病理相关。这些有机硼烷的独特机制是少数不基于氢原子转移过程的 RTA
The conformation of resorcin[4]arene cavitand system 1 was controlled by DMSO through a hydrogen bonding network between benzodiazaborole NHs of the cavitand flaps and DMSO molecules to stabilize the vase form. Subsequently, a guest-binding cavity of 1 was formed to accommodate tetraalkylammonium guest 3, permitting the monitoring of the guest by the unaided eye as a result of a CH-pi interaction between the benzodiazaborole pi-donor group and the guest.
An umpolung strategy for rapid access to thermally activated delayed fluorescence (TADF) materials based on phenazine
作者:Huaxing Zhang、Qiang Guo、Hu Cheng、Chunhao Ran、Di Wu、Jingbo Lan
DOI:10.1039/d1cc06705b
日期:——
radical nucleophilic addition/rearrangement of 2-aryl diazaboroles has been accomplished for the first time to construct phenazine structures. This protocol is an umpolung strategy based on the classical electrophilic mechanism, and therefore, a reversed regioselectivity was observed, which provides an opportunity to prepare sterically hindered phenazines. The resulting thermally activated delayed fluorescence
Interrupted Homolytic Substitution Enables Organoboron Compounds to Inhibit Radical Chain Reactions Rather than Initiate Them
作者:Zijun Wu、Robynne Vlaming、Michael Donohoe、Derek A. Pratt
DOI:10.1021/jacs.3c12438
日期:2024.1.10
antioxidants (RTAs). Mechanistic studies reveal that this is because the radical “ate” complexesderivedfrom peroxyl radical addition to boron are sufficiently persistent to trap another radical in an interrupted SH2 reaction. Remarkably, the reactivity of these organoboranes as inhibitors of autoxidation was shown to translate from simple hydrocarbons to the phospholipids of biological membranes such that
有机硼烷与过氧自由基的反应是其用作大量自由基链式反应的自由基引发剂的关键,特别是在需要高立体选择性或区域选择性的低温下。虽然这些反应通常通过一致的均解取代 (S H 2) 机制进行,但带有可稳定四配位硼自由基“ate”复合物的基团的有机硼烷(例如儿茶酚硼烷)通过逐步添加/断裂顺序进行该反应,并用作有用的化学计量烷基自由基前体。在这里,我们表明,分别衍生自儿茶酚硼烷和二氨基萘硼烷的芳基硼酸酯和酰胺是有效的自由基捕获抗氧化剂(RTA)。机理研究表明,这是因为过氧自由基与硼加成产生的自由基“吃”络合物足够持久,可以在中断的 S H 2 反应中捕获另一个自由基。值得注意的是,这些有机硼烷作为自动氧化抑制剂的反应性被证明可以从简单的碳氢化合物转化为生物膜的磷脂,从而可以抑制铁死亡,这是由脂质自动氧化驱动的细胞死亡方式,与神经变性和其他主要病理相关。这些有机硼烷的独特机制是少数不基于氢原子转移过程的 RTA