Basicity-Controlled [3+2] Cyclization of 3-Hydroxyquinolin-ones and beta-Chlorinated Nitrostyrenes

The construction of novel skeletons through the recombination of natural products ring systems is attractive. Herein, a basicity-controlled synthesis of (dihydro)furo[2,3-c]quinolin-4(5H)-one derivatives through (3+2) cyclization between 3-hydroxyquinolin-2-ones and beta-chlorinated nitrostyrenes was developed. In addition, preliminary study gave the chiral dihydrofuro[2,3-c]quinolin-4(5H)-one derivatives with up to 83 % ee.