Arylation, Alkenylation, and Alkylation of 2-Halopyridine <i>N</i>-Oxides with Grignard Reagents: A Solution to the Problem of C2/C6 Regioselective Functionalization of Pyridine Derivatives
alkenylation, and alkylation of functionalized 2-halopyridine N-oxides with various Grignard reagents was developed. It represented a highly efficient and selective C–H bond functionalization of pyridine derivatives in the presence of reactive C–Cl or C–Br bonds. Using Cl or Br as a blocking group, C2/C6 site-controllable functionalization of pyridine derivatives has been achieved. Various pyridine compounds