Primary alanes and alanates: useful synthetic reagents in aluminum chemistry

Primary alanes [RAlH2](2) can be stabilized kinetically by employment of ve ry bulky alkyl or aryl substituents. They are easily prepared by reacting t he appropriate lithium trihydroalanate precursor with organic halides, anhy drous hydrogen halides or halogens. Reactions of these aluminum hydrides wi th a wide variety of substrates ranging from protic reagents such as water, alcohols, amines, phosphines or thiols over ketones, nitriles or isonitril es to silylated species such as siloxanes or silyl halides are presented. P rimary alanes were shown to be unique starting materials for a number of in teresting compounds that were otherwise not accessible, or only available i n low yields. In addition, postulated intermediates of aluminum hydride red uctions of organic substrates such as ketones or nitriles can be isolated w hen using bulky primary alanes. (C) 2000 Elsevier Science Ltd. All rights r eserved.