Ligand-Promoted C3-Selective Arylation of Pyridines with Pd Catalysts: Gram-Scale Synthesis of (±)-Preclamol

Coupling of aryl halides with pyridines through a C3 activation.

Here we have another paper on C-H activation. And once again, its focused on pyridines. What makes it different is that the position being activacted is not the C2, but the C3. The people in Syngenta describe the coupling of different pyridines with aryl bromides and iodides. More than 25 examples are described. The reaction works also in a scale of grams and uses off-the-shelf reagents.

J. Am. Chem. Soc., 2011, 133 (47), pp 19090–19093. See: 10.1021/ja209510q