Diallylaluminium-N,N-dimethylaminoethanolate, the first stable allyl-alane suitable for additions to aldehydes, ketones and imines

The reaction of AlCl3 with lithium-N,N-dimethylaminoethanolate (3) in a 1:1 ratio yields the corresponding organo-aluminium chloride [Cl2Al(μ-OCH2CH2NMe2)]2 (1) from which the diallyl derivative [(CH2CHCH2)2Al(μ-OCH2CH2NMe2)]2 (4) was synthesized by treatment with 2 equiv. of allyl magnesium bromide. The structures of 1 and 4 were deduced from the 1H, 13C, 27Al NMR spectra and confirmed by X-ray structural determination. The allyl aluminium complex 4 was found to be a useful reagent for the transfer of one allyl group to aldehydes, imines and enones. The 1,2-addition products are formed in high yields.