A reagent for heteroatom borylation, including iron mediated reductive deoxygenation of nitrate yielding a dinitrosyl complex
作者:Daniel M. Beagan、Veronica Carta、Kenneth G. Caulton
DOI:10.1039/d0dt00077a
日期:——
4,4'-Bipyridyl is shown to be a catalyst for transfer of pinacolboryl groups from (Bpin)2 to nitrogen heterocycles and to Me3SiN3. Using stoichiometric (Bpin)2(pyrazine) or (Bpin)2(bipyridine) in an analogous manner, an aromatic nitro group is deoxygenated and subsequently borylated, and four-fold deoxygenation of (DIM)Fe(NO3)2(MeCN) to yield the dinitrosyl complex (DIM)Fe(NO)2 is facile. The co-product
Pyrazines and substituted pyrazines undergo addition of boron reagents having B–B, Si–B, and H–B bonds under transition-metal-free conditions, leading to high-yield synthesis of N-borylated 1,4-dihydropyrazines and 1,2,3,4-tetrahydropyrazine.
A Redox‐Active Tetrazine‐Based Pincer Ligand for the Reduction of N‐Oxyanions Using a Redox‐Inert Metal
作者:Daniel M. Beagan、Nicholas A. Maciulis、Maren Pink、Veronica Carta、I. J. Huerfano、Chun‐Hsing Chen、Kenneth G. Caulton
DOI:10.1002/chem.202101302
日期:2021.8.11
considerable hydrogen bonding potential of the dihydrotetrazine ring NH groups. The (H4btzp)ZnCl2 complex does not bind zinc in the pincer pocket, but instead H4btzp becomes a bridge between neighboring atoms through tetrazine nitrogen atoms, forming a polymeric chain. The reaction of AgNO2 with (H4btzp)ZnCl2 is shown to proceed with fast nitrite deoxygenation, yielding water and free NO. Half of the
研究了双四嗪基吡啶配体 (btzp) 对与锌配位的氮氧阴离子的反应化学,以探索在金属没有氧化还原活性的情况下用氧化还原活性配体还原NO x -底物。根据X=Cl、NO 3和 NO 2的 (btzp)ZnX 2 的合成和表征,以两个氮氧阴离子的 O-Zn 键为特征,表明甲硅烷基化剂选择性地将甲硅烷基取代基传递给四嗪氮,而不会对其进行还原脱氧NO x -1。高度氢化的H 4 的新合成btzp,包含两种二氢四嗪还原剂,描述了 (H 4 btzp)ZnX 2的合成和表征,用于 X=Cl 和 NO 3,这两者都显示出二氢四嗪环 NH 基团的相当大的氢键势。(H 4 btzp)ZnCl 2复合物不结合钳状袋中的锌,而是H 4 btzp 通过四嗪氮原子成为相邻原子之间的桥梁,形成聚合物链。AgNO 2与(H 4 btzp)ZnCl 2的反应显示进行快速亚硝酸盐脱氧,产生水和游离NO。H 4 的一半btzp
Chemodivergent Organolanthanide-Catalyzed C–H α-Mono-Borylation of Pyridines
作者:Jacob O. Rothbaum、Alessandro Motta、Yosi Kratish、Tobin J. Marks
DOI:10.1021/jacs.2c06844
日期:2022.9.21
metathesis. Notably, varying the lanthanide identity and substrate substituent electronic character promotes marked chemodivergence of the catalytic selectivity: smaller/more electrophilic lanthanide3+ ions and electron-rich substrates favor selective α-C–H functionalization, whereas larger/less electrophilic lanthanide3+ ions and electron-poor substrates favor selective B–N bond-forming 1,2-dearomatization
Mechanistic insights into the dearomative diborylation of pyrazines: a radical or non-radical process?
作者:Liuzhou Gao、Hanyin Zhang、Xueting Liu、Guoqiang Wang、Shuhua Li
DOI:10.1039/d1dt00921d
日期:——
hindered pyrazine (2,3-dimethylpyrazine). For the diboration reaction of 2,3-dimethylpyrazine with B2pin2 in the presence of 2,6-dichloro-4,4′-bipyridine as the catalyst, 4,4′-bipyridine-mediated radical pathway proceeding through a B–B homolytic cleavage/boryl radical addition is preferred. Control experiments combined with kinetic studies provided supportive evidence for the proposed mechanism.