2‐Pyridyl Sulfoxide: A Versatile and Removable Directing Group for the Pd
<sup>II</sup>
‐Catalyzed Direct CH Olefination of Arenes
作者:Alfonso García‐Rubia、M. Ángeles Fernández‐Ibáñez、Ramón Gómez Arrayás、Juan Carlos Carretero
DOI:10.1002/chem.201003633
日期:2011.3.21
Removable and versatile: The 2‐pyridylsulfinyl group has proved to be an efficient directinggroup in the PdII‐catalyzed aryl ortho CH olefination. This catalyst system enables the sequential double olefination to give asymmetrically di‐ortho‐functionalized arenes. The sulfinyl directinggroup can be easily cleaved, providing access to 1,3‐disubstituted arenes, or transformed into a thiol group.
Pd(II)-catalyzed C–H olefination of aryl 2-pyridyl sulfoxides with unactivated and activated olefins has been demonstrated. We employed environmentally benign and inexpensive molecular oxygen as the sole oxidant. The versatile nature of the 2-pyridyl sulfoxide directinggroup has been proven by its transformation to the sulfone functionality. Deuterium scrambling experiments and intramolecular kinetic
Palladium-Catalyzed Regioselective Arylation of Arene C-H Bond Assisted by the Removable 2-Pyridylsulfinyl Group
作者:Yuhong Zhang、Xunbin Zhang、Ming Yu、Jinzhong Yao
DOI:10.1055/s-0031-1290320
日期:2012.2
A palladium-catalyzed arylation of arene C-H bond assisted by a removable 2-pyridylsulfinyl group is described. The reaction employs aryltrifluoroborates as the arylation reagent, leading to the corresponding products in moderate to good yield with broad substrate scope. The directinggroup can be removed or converted to other useful functionalities, which showcases the potential synthetic application
Modulation of photochemical oxidation of thioethers to sulfoxides or sulfones using an aromatic ketone as the photocatalyst
作者:Bin Zhao、Gerald B. Hammond、Bo Xu
DOI:10.1016/j.tetlet.2021.153376
日期:2021.10
We have developed an eco-friendly and chemo-selective photocatalytic synthesis of sulfoxides or sulfones via oxidation of sulfides (thioethers) at ambient temperature using air or O2 as the oxidant. An inexpensive thioxanthone was used as the photocatalyst. Our method offers excellent chemical yields and good functional group tolerance. The hydrogen bonding between hexafluoro-2-propanol (HFIP) and
我们开发了一种环保且化学选择性的光催化合成亚砜或砜,通过在环境温度下使用空气或 O 2作为氧化剂氧化硫化物(硫醚)。廉价的噻吨酮被用作光催化剂。我们的方法提供了出色的化学产率和良好的官能团耐受性。六氟-2-丙醇 (HFIP) 和亚砜之间的氢键可能在最大限度地减少亚砜的过度氧化方面发挥重要作用。
Modifiable Sulfur Tethers as Directing Groups for Aromatic CH Acetoxylation Reactions
作者:Heinrich Richter、Stephan Beckendorf、Olga García Mancheño
DOI:10.1002/adsc.201000941
日期:2011.2.11
A designed new class of modifiable sulfur tethers for aromatic CH bond functionalizations is presented. As a model, the palladium-catalyzed directed acetoxylation reaction was studied. The more challenging sulfoxide tethers were the most effective in this transformation, showing a broad functionality tolerance, high S oxido-redox stability and no catalyst poisoning. Preliminary mechanistic studies