Several 1, 5-diketones have been prepared in good to excellent yields by versatile conjugate addition of nucleophiles such as cyclic or acyclic ketones, amines and thiols to α, β-unsaturated enones and alkynones, in the presence of catalytic amounts of 10% aq NaOH, TBAI and DMSO at ambient temperature. The choice of solvent and phase-transfer catalyst played a critical role in improving the reaction rate and yields of the products.
