Acylstannanes were found to add to such α,β-unsaturated carbonyl compounds as enones or ynoates in the presence of a nickel or palladium catalyst to give 2-stannyl-4-oxoalk-2-enoates or 1,4-diketones, whereas the three component coupling between acylstannanes, enones and aldehydes provided 2-hydroxymethyl 1,4-diketones.