Catalytic Asymmetric Michael Addition Of Malonate Derivatives To Chalcone

Recently, catalytic asymmetric Michael addition of carbon nucleophiles toα,β-unsaturated compounds has become an emerging field of organic chemistry. This significant protocol provides one of the most economical and efficient approaches for the carbon-carbon, carbon-heteroatom bond-forming. However, in terms of Michael addition reactions of malonic esters and their derivatives to chalcone, most chiral phase-transfer catalysts showed weak activity and enantioselectivity. Therefore, one crucial objective is the design and synthesis of new chiral phase-transfer catalyst.According to the analyses made above, we are ready to try the asymmetric Michael addition of malonic esters and N-acetylaminomalonate to chalcone. Two double-spiro chiral phase-transfer catalysts were synthesized from the optically pure 1,1'-binaphthol through four steps. Then, the model reaction of N-acetylamino- malonate to chalcone was carried out in the presence of the catalyst and gave the corresponding addition products with 81% yield, 59% ee.Furthermore, we choose the model reaction of dimethyl malonate to chalcone by the double-spiro chiral phase-transfer catalysts and other majorizations, giving high yield (up to 99%) and moderate enantioselectivities (up to 66% ee).