A Simple and Convenient Method for Synthesizing Trialkoxyboranes and Trialkoxyboroxins Using Calcium Hydride as a Drying Agent

Trialkoxyboranes are conveniently synthesized in good to excellent yields from the corresponding alcohols or phenols and boric acid using calcium hydride as a drying agent. This method is successful for a variety of sterically hindered alcohols. In a new general route, trialkoxyboroxins are formed under mild reaction conditions from these same readily available materials. The trialkoxyboranes and trialkoxyboroxins can be interconverted by addition of stoichiometric amounts of boric acid or the alcohols/phenols, in the presence of calcium hydride. Calcium hydride is most effective for the removal of water. This allows for a simple and convenient route for the preparation of the useful trialkoxyboranes and the previously inaccessible trialkoxyboroxins, for further investigation or applications.