The von Braun Reaction Applied to Azetidines

The von Braun reaction, that is the reaction of cyanogen bromide with tertiary amines, was applied to a series of functionalized N-alkyl azetidines. This reaction mainly leads to the cleavage of the strained four-membered ring, producing 3-bromo N-alkyl cyanamides in good yield and variable regioselectivity, which can be used as original building blocks for the synthesis of nitrogen heterocycles.