A General Method for Palladium-Catalyzed Reactions of Primary Sulfonamides with Aryl Nonaflates
摘要:
A general method for Pd-catalyzed sulfonamidation of aryl nonafluorobutanesulfonates (aryl nonaflates) is described. A biaryl phosphine ligand, t-BuXPhos, formed the most active catalyst, and K3PO4 in tert-amyl alcohol was found to be the optimal base solvent combination for the reaction. The reaction conditions were tolerant of various functional groups such as cyano, nitro, ester, aldehyde, ketone, chloride, carbamate, and phenol. Heterocyclic aryl nonaflates were found to be suitable coupling partners. High yields of the coupled products were obtained from the reactions between inherently disfavored substrates such as electron-rich nonaflates and electron-poor sulfonamides. Kinetic data suggest reductive elimination to be the rate-limiting step for the reaction. The only limitation of this methodology that we have identified is the inability of 2,6-disubstituted aryl nonaflates to efficiently participate in the reaction.
Copper-Catalyzed Redox Coupling of Nitroarenes with Sodium Sulfinates
作者:Saiwen Liu、Ru Chen、Jin Zhang
DOI:10.3390/molecules24071407
日期:——
A simple copper-catalyzed redox coupling of sodiumsulfinates and nitroarenes is described. In this process, abundant and stable nitroarenes serve as both the nitrogen sources and oxidants, and sodiumsulfinates act as both reactants and reductants. A variety of aromatic sulfonamides were obtained in moderate to good yields with broad substrate scope. No external additive is employed for this kind
Nitrosoarenes as Nitrogen Source for Generation of Sulfonamides with the Insertion of Sulfur Dioxide under
<scp>Metal‐Free</scp>
Conditions
<sup>†</sup>
A metal‐free reaction of nitrosoarenes, aryldiazonium tetrafluoroborates, and sulfur dioxide under mild conditions is developed, giving rise to sulfonamides in moderate to good yields. This transformation proceeds efficiently at room temperature in the presence of cyclohexa‐1,4‐diene with a broad reaction scope. Good functional group compatibility is observed, including cyano, halo, and ester. A plausible