Cristina Sicre, J. Alonso-Gómez, M. Cid
Nov 27, 2006
Citations
1
Influential Citations
33
Citations
Journal
Tetrahedron
Abstract
Abstract 2,4-Dibromopyridine undergoes a regioselective Suzuki cross-coupling reaction at position 2 with several alkenyl(aryl) boronic acids to render 4-bromo-2-carbon substituted pyridines, difficult to be prepared otherwise, in good yields under palladium catalysis, either Pd(PPh3)4/TlOH or Pd2dba3/PCy3/K3PO4 at 25 °C. This behavior is explained on the basis of the electrophilic character of both C–Br bonds, being their relative reactivity in 2,4-dibromopyridine similar to that in the corresponding monobromopyridines. In addition, the dicoupled compound 6 is not formed through a double oxidative addition of 2,4-dibromopyridine to Pd(PPh3).