对(氧化)金催化的选定关键反应的广泛动力学研究集中在催化活性的降低,这是由于吡啶衍生物引起的金(I)催化剂的抑制,如果使用N氧化物作为副产物获得的吡啶衍生物氧气供体。不管它们的市售性如何,都已对受检吡啶衍生物及其相应的N-氧化物进行了选择。特别注意的是迄今为止在大多数反应筛选中都被忽略的实际益处。用GC和1监测测试反应1 H NMR光谱。所接收的反应常数提供了关于杂环的电子结构与催化活性之间的相关性的信息。根据收集的动力学数据,有可能开发出一套基本的三种N氧化物,这些氧化物必须在进一步的氧化金(I)催化反应中加以考虑。
(-)-citrinadin A 的第一个对映选择性全合成是通过 20 个步骤从市售材料通过最小化再官能化和保护/脱保护操作的方法完成的。该合成的基石是将二烯醇盐不对称地加成到手性吡啶鎓盐中以设置初始手性中心。一系列底物控制的反应,包括高度立体选择性环氧化/开环序列和吲哚的氧化重排以提供螺吲哚,然后用于在 (-)-citrinadin A 的五环核心中建立剩余的立体中心。 citrinadin A 的成功合成导致了citrinadin 核心亚结构立体化学结构的修订。
Catalytic N-oxidation of tertiary amines on RuO2NPs anchored graphene nanoplatelets
作者:Mayakrishnan Gopiraman、Hyunsik Bang、Sundaram Ganesh Babu、Kai Wei、Ramasamy Karvembu、Ick Soo Kim
DOI:10.1039/c3cy00963g
日期:——
pattern (XRD) of GNPs–RuO2NPs revealed that the chemical state of Ru on GNPs was +4. After the optimization of reaction conditions for N-oxidation of triethylamine, the scope of the reaction was extended to various aliphatic, alicyclic and aromatic tertiaryamines. The GNPs–RuO2NPs showed excellent catalytic activity in terms of yields even at a very low amount of Ru catalyst (0.13 mol%). The GNPs–RuO2NPs
Hydroheteroarylation of Unactivated Alkenes Using <i>N</i>-Methoxyheteroarenium Salts
作者:Xiaoshen Ma、Hester Dang、John A. Rose、Paul Rablen、Seth B. Herzon
DOI:10.1021/jacs.7b02388
日期:2017.4.26
reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%)
Clean protocol for deoxygenation of epoxides to alkenes <i>via</i> catalytic hydrogenation using gold
作者:Jhonatan L. Fiorio、Liane M. Rossi
DOI:10.1039/d0cy01695k
日期:——
The epoxidation of olefin as a strategy to protect carbon–carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available
B(C<sub>6</sub>
F<sub>5</sub>
)<sub>3</sub>
-Catalyzed Deoxygenation of Sulfoxides and Amine <i>N</i>
-Oxides with Hydrosilanes
作者:Fangwei Ding、Yanqiu Jiang、Shaoyan Gan、Robert Li-Yuan Bao、Kaifeng Lin、Lei Shi
DOI:10.1002/ejoc.201700489
日期:2017.6.30
An efficient strategy for the deoxygenation of sulfoxides and amine N-oxides using B(C6F5)3 and hydrosilanes has been developed. The method affords the corresponding aromatic or aliphatic products in good to high yields, and shows good functional group tolerance under mild conditions.
Insights into the mechanistic and synthetic aspects of the Mo/P-catalyzed oxidation of N-heterocycles
作者:Oleg V. Larionov、David Stephens、Adelphe M. Mfuh、Hadi D. Arman、Anastasia S. Naumova、Gabriel Chavez、Behije Skenderi
DOI:10.1039/c4ob00115j
日期:——
Mechanistic and synthetic studies of the Mo/P-catalyzed N-oxidation of N-heterocycles with hydrogen peroxide shed light on the role and nature of the catalytically active species.