Potassium hydride is a highly reactive reagent for the metalation of highly hindered alcohols, amines, phenols, ketones, sulfoxides, etc.2 The reactivity exhibited by this hydride is far superior to the other, more commonly used, alkali metal hydrides. In addition, potassium hydride is exceptionally reactive toward weak Lewis acids, such as trialkylboranes and trialkoxyboranes.3 Unlike lithium and sodium hydrides, potassium hydride reacts with hindered organoboranes, such as tri-sec-butylborane, rapidly and quantitatively, even at room temperature. The correspending potassium trialkylborohydrides are formed in quantitative yield under such mild conditions. © 1986, American Chemical Society. All rights reserved.