Bifunctional thiosquaramide catalyzed asymmetric reduction of dihydro-β-carbolines and enantioselective synthesis of (−)-coerulescine and (−)-horsfiline by oxidative rearrangement

RSC Advances
2020.0

Abstract

Tetrahydro-beta-carboline (THBC) is a tricyclic ring system that can be found in a large number of bioactive alkaloids. Herein, we report a simple and efficient method for the synthesis of enantiopure THBCs through a chiral thiosquaramide (11b) catalyzed imine reduction of dihydro-beta-carbolines (17a-f). The in situ generated Pd-H employed as hydride source in the reaction of differently substituted chiral THBCs (18a-f) afforded high selectivities (R isomers, up to 96% ee) and good isolated yields (up to 88%). Moreover, the chiral thiosquaramide used also afforded exceptional catalyst activity in the syntheses of (-)-coerulescine (5) and (-)-horsfiline (6) with excellent enantioselectivities up to 98% and 93% ee, respectively, via an enantioselective oxidative rearrangement approach.

Knowledge Graph

Similar Paper

Bifunctional thiosquaramide catalyzed asymmetric reduction of dihydro-β-carbolines and enantioselective synthesis of (−)-coerulescine and (−)-horsfiline by oxidative rearrangement
RSC Advances 2020.0
A review of synthetic bioactive tetrahydro-β-carbolines: A medicinal chemistry perspective
European Journal of Medicinal Chemistry 2021.0
Synthesis, structure–activity relationship, and biological evaluation of quinolines for development of anticancer agents
Archiv der Pharmazie 2023.0
Synthesis of Racemic and Enantiopure Forms of β-Carboline Alkaloid Brevicolline
Synthesis 2022.0
Controlling stereoselectivity by enzymatic and chemical means to access enantiomerically pure (1S,3R)-1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline derivatives
Tetrahedron: Asymmetry 2013.0
Cobalt-Catalyzed Enantioselective C–H Annulation of Benzylamines with Alkynes: Application to the Modular and Asymmetric Syntheses of Bioactive Molecules
Journal of the American Chemical Society 2023.0
Photocatalytic enantioselective Minisci reaction of β-carbolines and application to natural product synthesis
Chemical Science 2022.0
Design, Synthesis and Antioxidant Activity of Tetrahydro-β-carbolines
Chinese Journal of Organic Chemistry 2023.0
A Catalytic Asymmetric Pictet–Spengler Platform as a Biomimetic Diversification Strategy toward Naturally Occurring Alkaloids
Journal of the American Chemical Society 2022.0
Studies on the total syntheses of β ‑carboline alkaloids orthoscuticellines A and B
Natural Product Research 2024.0