Organocatalyzed regioselective and enantioselective synthesis of 1,4- and 1,2-dihydropyridines

Abstract

Herein, we introduce one of the first examples of asymmetric organocatalyzed synthesis of 1,2-dihydropyridines, affording enantioselective access to and partially solving regioselectivity challenges in the synthesis of dihydropyridines. We demonstrate that through modification of organocatalysts both 1,2- and 1,4-dihydropyridines (1,2- and 1,4-DHPs) can be obtained with high regioselectivity (ratio of 1,2-DHP/1,4-DHP from 95/5 to 0/100) and enantioselectivity (33% ee for 1,2-DHPs and up to 98% ee for 1,4-DHPs) in good yields (up to 87%).

Graphical Abstract

Keywords:

• Asymmetric synthesis
• chiral secondary amine
• dihydropyridine
• enantioselective organocatalysis

Additional information

Funding

This research is

funded by the Graduate University of Science and Technology under [grant number GUST.STS.ĐT2017-HH10] and Vietnamese National Foundation for Science and Technology Development (NAFOSTED, code: 104.01-2017.27).