Palladium(II)-Catalyzed Direct Ortho Arylation of 4-Methyl-N-phenylpyridin-2-amines via C–H Activation/C–C Coupling and Synthetic Applications
摘要:
The direct ortho arylation of 4-methyl-N-phenylpyridin-2-amines via palladium(II)-catalyzed C-H activation is described. Treatment of 4-methyl-N-phenylpyridin-2-amine with potassium aryltrifluoroborate using 10 mol % of palladium(II) acetate as the catalyst, 2 equiv of copper(II) acetate as the oxidant, and 1 equiv of p-benzoquinone in tert-butyl alcohol gave ortho-arylated products in modest to excellent yields. This reaction shows good functional group compatibility. A series of H-1 NMR titration experiments and controlled experiments elucidating the reaction mechanism were carried out. The key intermediate, 4-methyl-N-phenylpyridin-2-amine palladacycle, was isolated and characterized by X-ray crystallography. The advanced transformations of ortho-phenylated 4-methyl-N-phenylpyridin-2-amine to N-(4-methylpyridin-2-yl)-9H-carbazole, biphenyl-2-amine, and 3-methyl-6-phenylpyrido[1,2-a]benzimidazole were successfully demonstrated as potential synthetic applications.
A compound represented by formula (I) or an isomer or a pharmaceutically acceptable salt thereof. The present invention also relates to an application of the same in preparing a drug for treating a disease related to a PGI2 receptor.
An Ir(III)-catalyzed relay aryl C–H bond carbenoidinsertion cascade of N-aryl-2-pyridinamines with diazo Meldrum'sacid has been developed. This method provides an efficient approach to multifunctionalized 1,3-dihydroindol-2-ones with a broad range of functional group tolerance. Furthermore, this protocol could be applied for the concise synthesis of bioactive hematopoietic growth factor analogues
A Rh(III)-catalyzed carboaminatiori of alkynyl cycloalkanols with arylamines has, been developed. This transformation involves a novel Csp(2)-H/Cse(3)-Cse(3) activation relay and provides an efficient approach to versatile 1,2,3-trisubstituted indoles with a broad range of functional group tolerance.