Fused N‐Heterocycles with Contiguous Stereogenic Centers Accessed by an Asymmetric Catalytic Cascade Reaction of Tertiary Enamides

Zhen, LiTong, ShuoZhu, JiepingWang, Mei‐Xiang2020-01-242020-01-242020-01-24202010.1002/chem.201904596https://infoscience.epfl.ch/handle/20.500.14299/164904We report in this article a cascade reaction strategy for the synthesis of complex N-heterocyclic compounds with contiguous and tetrasubstituted stereogenic carbons. Under the sequential catalysis of a chiral binol–Ti complex and BF3, cyclopentanone-derived tertiary enamides undergo an enantioselective enamine addition to ketone carbonyls followed by diastereoselective trapping of the resulting acyliminiums by electron-rich aryl moieties to furnish four- and five-membered ring-fused N-heterocyclic products as the sole diastereomers in high yields with up to 99%ee.alkaloidsasymmetric synthesiscascade reactionscyclizationtertiary enamidesFused N‐Heterocycles with Contiguous Stereogenic Centers Accessed by an Asymmetric Catalytic Cascade Reaction of Tertiary Enamidestext::journal::journal article::research article