Triethylamine alane

Steroids s. id, 211 with triethylamine alane cf. S. Cacchi, B. Giannoli, and D. Misiti, Synthesis 1974, 728 with isobutylaluminum dichloride prepared in situ from triisobutylaluminum and AICI3 cf. H. Pauling, Helv. 58, 1781 (1975)... 

Triethylamine alane Sec. alcohols from ketones Stereospecific reduction Steroids... 

Alane s. a. Triethylamine alane Alanes (s. a. Aluminum compds., organo-)... 

The X-ray structural characterization of a series of mono-, di-, and poly-lanthanidocene aluminohydride and alane complexes by B.M. Bulychev and G.L. Soloveichik revealed a variety of coordination modes of the [A1H4] , [AIH3] and [A1H2]+ moieties [273-281]. Routinely, these complexes were synthesized by the reaction of a lanthanidocene chloride with LiAlH4 or A1H3. The nuclearity and All x coordination mode depend on the presence of additional Lewis bases, such as THF, diethyl ether, or triethylamine (Chart 7). Diene polymerization based on lanthanidocene aluminohydrides has not been reported. 

The phosphine-alane is expected to displace PPh at Ni, but no reaction takes place in the absence of substrate due to strong intramolecular P Al interactions. Lewis bases such a triethylamine are able to split the head-to-tail phosphine-alane dimer and consistently, further increase catalytic activity. The precise role of the Lewis acid moiety in the catalytic cycle remains unknown. It is supposed to interact with the methyl group at Ni and to facilitate methyl/silyl exchange. The key active species 36a could not be characterized, but its Lewis base adduct 36b was identified by NMR (Figure 19). 

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