AMINOBOROHYDRIDES .4. THE SYNTHESIS AND CHARACTERIZATION OF LITHIUM AMINOBOROHYDRIDES - A NEW CLASS OF POWERFUL, SELECTIVE, AIR-STABLE REDUCING AGENTS

Lithium aminoborohydrides (LiABH(3)) are a new class of powerful yet selective reducing agents that reproduce, in air, virtually all of the transformations for which lithium aluminum hydride is now used. LiABH(3)'s can be readily prepared as solids or generated in situ, are nonpyrophoric, and liberate hydrogen only slowly with protic solvents above pH 4. LiABH(3)'s can be handled in dry air as easily as sodium borohydride and retain their chemical activity for at least 6 months when stored under nitrogen or dry air at 25 degrees C. LiABH(3)'s can be synthesized from any primary or secondary amine, thus allowing control of the steric and electronic environment of these reagents.