Shedding light on Brønsted acid catalysis – a photocyclization–reduction reaction for the asymmetric synthesis of tetrahydroquinolines from aminochalcones in batch and flow
Visible-Light Induction/Brønsted Acid Catalysis in Relay for the Enantioselective Synthesis of Tetrahydroquinolines
作者:Wenhui Xiong、Shan Li、Bo Fu、Jinping Wang、Qiu-An Wang、Wen Yang
DOI:10.1021/acs.orglett.9b01354
日期:2019.6.7
An efficient method merging Brønsted acid catalysis with visible-light induction for the highly enantioselectivesynthesis of tetrahydroquinolines has been developed. This mild process directly transforms 2-aminoenones into 2-substituted tetrahydroquinolines with excellent enantioselectivities through a relay visible-light-induced cyclization/chiral phosphoric acid-catalyzed transfer hydrogenation
A solvent-controlled catalyst-free chemoselective reaction was developed. Both 3,4-dihydroquinazoline-2-thiones and 2-imino[1,3]benzothiazines could be efficiently constructed by the reaction of 2-amino chalcones with isothiocyanates via two different chemoselective reactions depending on the solvents. The reaction was modulated by the solvents to proceed via either aza-Michael addition or thia-Michael