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.
Palladium-catalyzed C–H activation reactions directed by a removable 2-pyridylsulfinyl group were developed. Aromatic olefination products were formed in good yields on treatment of 2-(phenylsulfinyl)pyridines with alkenes in the presence of a Pd catalyst. The reaction tolerates a wide range of substituted alkenes, including various acrylates and styrenes. The controlled experiments indicated that
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
constrained binuclear palladium catalyst system affords selective thioetherification of a wide range of functionalized arenethiols with chloroheteroaromatic partners with the highest turnover numbers (TONs) reported to date and tolerates a large variety of reactive functions. The scope of this system includes the coupling of thiophenols with six‐ and five‐membered 2‐chloroheteroarenes (i.e., functionalized
provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium–1,1′-bis[(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance