Asymmetric synthesis of tetrahydropyran[3,2-c]quinolinones via an organocatalyzed formal [3+3] annulation of quinolinones and MBH 2-naphthoates of nitroolefin

Publication date: Available online 23 August 2019Source: Chinese Chemical LettersAuthor(s): Jian Li, Qi-Long Hu, Xue-Ping Chen, Ke-Qiang Hou, Albert S.C. Chan, Xiao-Feng XiongAbstractAn efficient asymmetric and enantio-swithchable organocatalytic [3+3] annulation reaction using MBH-2-naphthoates of nitroalkenes and 4-hydroxyquinolin-2(1H)-ones has been developed. Densely substituted tetrahydropyrano[3,2-c]quinolinones scaffolds with two adjacent stereogenic centers are obtained with high yield (up to 95% yield) and good stereoselectivities (up to>20:1 dr and 96% ee) in an enantio-switchable manner. Furthermore, gram scale synthesis was achieved and the nitro group could easily transform into an amino group without any appreciable loss in the diastereo- and enantioselectivity.Graphical abstractAn efficient asymmetric and enantio-swithchable organo-catalytic construction of tetrahydropyrano[3,2-c]quinolinones scaffolds were developed.

Source: Chinese Chemical Letters - August 25, 2019 Category: Chemistry Source Type: research