Aminoborohydrides 15. The First Mild and Efficient Method for Generating 2-(Dialkylamino)-pyridines from 2-Fluoropyridine

Abstract

[reaction: see text] Lithium aminoborohydride (LAB) reagents promote the amination of 2-fluoropyridine under mild reaction conditions, providing 2-(dialkylamino)pyridines in excellent yield and purity. Treatment of 2-fluoropyridine with 1.1 equiv of lithium aminoborohydride at room temperature affords complete conversion after 1 h. This is the first general way by which 2-(dialkylamino)pyridines may be directly obtained from fluoropyridines under ambient reaction conditions. 2-Chloropyridine can also be converted to 2-(dialkylamino)pyridine by simply increasing the number of LAB equivalents and the reaction temperature.