Transition‐Metal‐Free Regioselective Alkylation of Pyridine N ‐Oxides Using 1,1‐Diborylalkanes as Alkylating Reagents

Reported herein is an unprecedented base‐promoted deborylative alkylation of pyridine N‐oxides using 1,1‐diborylalkanes as alkyl sources. The reaction proceeds efficiently for a wide range of pyridine N‐oxides and 1,1‐diborylalkanes with excellent regioselectivity. The utility of the developed method is demonstrated by the sequential C−H arylation and methylation of pyridine N‐oxides. The reaction also can be applied for the direct introduction of a methyl group to 9‐O‐methylquinine N‐oxide, thus it can serve as a powerful method for late‐stage functionalization.