Tandem reaction of 1,2-allenic ketone with α-halo ketone or α-halo ester in water: an efficient and sustainable synthesis of 1,3,4′-tricarbonyl compounds

An efficient and sustainable synthesis of the otherwise difficult to obtain 1,3,4′-tricarbonyl compounds through a water mediated, TBAF·3H2O promoted unprecedented tandem reaction of 1,2-allenic ketone with α-halo ketone or α-halo ester has been developed. Remarkably enhanced reactivity and improved chemoselectivity by using water as the reaction medium was observed. The 1,3,4′-tricarbonyl compounds facilitate further versatile transformations, which underscores the importance of these products as synthetic intermediates.