Metalloaldimines. 4. Reaction of Lithium Aldimines with Carbonyl Compounds and with Activated Alkyl Halides

Article abstract of DOI:10.1021/jo00339a033

Lithium aldimines, acyl anions derived from isocyanides and organolithium reagents, add to aldehydes to give, after quenching with water, α-amino ketones.These products result from an Almadori rearrangement of the α-hydroxy imine precursor.The intermediate alkoxides are trapped by trimethylsilyl chloride to give α-trimethylsiloxy imines.Lithium aldimines add exclusively 1,2 to acrolein but add exclusively 1,4 to methyl acrylate.Hydrolysis of these imine products gives the corresponding carbonyl compounds.Lithium aldimines also couple with benzyl bromide to give upon hydrolysis the benzyl ketone.Coupling of lithium aldimines with allyl bromide yields an E,Z mixture of α,β-unsaturated imines.