Palladium-catalysed cross-coupling reactions of arylboronic acids with π-deficient heteroaryl chlorides
作者:Naji M. Ali、Alexander McKillop、Michael B. Mitchell、Ricardo A. Rebelo、Philip J. Wallbank
DOI:10.1016/s0040-4020(01)80481-6
日期:1992.1
The palladium-catalysed cross-coupling reactions of arylboronic acids with a variety of pi-deficient heteroaryl chlorides proceed in high yield. [1,4-Bis(diphenylphosphino)butane]palladium(II) dichloride was found to be a very satisfactory catalyst for monocyclic heteroaryl chlorides, whereas tetrakis(triphenylphosphine)palladium(O) was found to be excellent for a range of chloroquinoline derivatives.
C–H Arylation of Pyridines: High Regioselectivity as a Consequence of the Electronic Character of C–H Bonds and Heteroarene Ring
作者:Pengfei Guo、Jung Min Joo、Souvik Rakshit、Dalibor Sames
DOI:10.1021/ja206022p
日期:2011.10.19
We report a new catalytic protocol for highly selective C-H arylation of pyridines containing common and synthetically versatile electron-withdrawing substituents (NO(2), CN, F and Cl). The new protocol expands the scope of catalytic azine functionalization as the excellent regioselectivity at the 3- and 4-positions well complements the existing methods for C-H arylation and Ir-catalyzed borylation, as well as classical functionalization of pyridines. Another important feature of the new method is its flexibility to adapt to challenging substrates by a simple modification of the carboxylic acid ligand or the use of silver salts. The regioselectivity can be rationalized on the basis of the key electronic effects (repulsion between the nitrogen lone pair and polarized C-Pd bond at C2-/C6-positions and acidity of the C-H bond) in combination with steric effects (sensitivity to bulky substituents).
87. Reactions of methazonic acid. Part I. The preparation of 3-nitrolepidines and 3-nitro-4-arylquinolines
作者:K. Schofield、R. S. Theobald
DOI:10.1039/jr9500000395
日期:——
Tawada Hiroyuki, Harcourt Myles, Kawamura Noriaki, Kajino Masahiro, Ishik+, J. Med. Chem, 37 (1994) N 13, S 2079-2084