Decarboxylative [3 + 2] cycloaddition of propargyl cyclic carbonates with ,-bis(nucleophile)s to access dihydrofuro[3,2-]coumarins and dihydronaphtho[1,2-]furans with quaternary center

The development of efficient and straightforward strategies for obtaining chiral complex molecules from readily available starting materials is of great value in drug discovery. The stereodivergent synthesis of heterocycles bearing quaternary centers remains a challenge due to inherent steric issues. Herein, we report an enantioselective copper-catalyzed decarboxylative [3 + 2] cycloaddition of propargyl cyclic carbonates/carbamates with 4-hydroxycoumarins to afford a wide range of dihydrofuro[3,2- c ]coumarins in excellent yields and enantioselectivity. The strategy has been successfully applied to other C , O -bisnucleophiles, such as α-naphthols, to obtain dihydronaphtho[1,2- b ]furans with good yields. Propargyl cyclic carbonates/carbamates were used as C 2 synthons towards the [3 + 2] cycloaddition of 4-hydroxycoumarins to generate dihydrofuro[3,2- c ]coumarins. Similarly, α-naphthols provided dihydronaphtho[1,2- b ]furans.