Cesium hydroxide promoted chemoselective N-alkylation for the generally efficient synthesis of secondary amines

[GRAPHICS] Selective N-alkylation of primary amines was developed using cesium hydroxi de to prepare various secondary amines efficiently. A cesium base not only promoted monoalkylations of primary amines but also suppressed overalkylati ons. Various amines and alkyl bromides were examined, and the preliminary r esults demonstrated this methodology was highly chemoselective, favoring mo no-N-alkylation over dialkylation. In particular, use of amino acid derivat ives afforded the desired secondary amines exclusively.