Base-induced Sommelet–Hauser rearrangement of N-(pyridinylmethyl) tetraalkylammonium salts

The base-induced Sommelet–Hauser (S–H) rearrangement of various types of N -(pyridinylmethyl) tetraalkylammonium salts 2 to produce N , N -dialkyl-α-pyridinylamino acid esters 4 was investigated. For example, a treatment of N -(2-pyridinylmethyl) glycine tert -butyl ester-derived tetraalkylammonium salt 2a with 1.2 equivalents of potassium tert -butoxide in THF at −40 °C gave the corresponding S–H product, tert -butyl 2-(dimethylamino)-2-(2-methylpyridin-3-yl)acetate ( 4a ), in 93% yield. Our method is an efficient C–H functionalization of pyridines under simple and mild conditions.