18161-94-9Relevant academic research and scientific papers
The Enantioselective Total Synthesis of Bisquinolizidine Alkaloids: A Modular “Inside-Out” Approach
Scharnagel, Dagmar,Goller, Jessica,Deibl, Nicklas,Milius, Wolfgang,Breuning, Matthias
, p. 2432 - 2435 (2018)
Bisquinolizidine alkaloids are characterized by a chiral bispidine core (3,7-diazabicyclo[3.3.1]nonane) to which combinations of an α,N-fused 2-pyridone, an endo- or exo-α,N-annulated piperidin(on)e, and an exo-allyl substituent are attached. We developed a modular “inside-out” approach that permits access to most members of this class. Its applicability was proven in the asymmetric synthesis of 21 natural bisquinolizidine alkaloids, among them more than ten first enantioselective total syntheses. Key steps are the first successful preparation of both enantiomers of C2-symmetric 2,6-dioxobispidine by desymmetrization of a 2,4,6,8-tetraoxo precursor, the construction of the α,N-fused 2-pyridone by using an enamine-bromoacrylic acid strategy, and the installation of endo- or, optionally, exo-annulated piperidin(on)es.
Cytisine as a scaffold for ortho-diphenylphosphinobenzenecarboxamide ligands for Pd-catalyzed asymmetric allylic alkylation
Philipova, Irena,Stavrakov, Georgi,Vassilev, Nikolay,Nikolova, Rositsa,Shivachev, Boris,Dimitrov, Vladimir
, p. 10 - 20 (2015/02/19)
Cytisine has been used as a scaffold for the synthesis of three novel phosphino-benzenecarboxamide ligands. The latter were obtained from cytisine and tetrahydrocytisine, and tetrahydrodeoxocytisine thereof. The structures and conformations of the newly p
Parallel solid-phase synthesis of novel 3,7-diazabicyclo[3.3.1]nonane derivatives starting from natural alkaloid cytisine
Sandulenko,Ivashchenko,Kravchenko,Tkachenko,Vvedensky
experimental part, p. 1999 - 2004 (2009/12/23)
A parallel solid-phase synthesis of combinatorial library of 436 amides of 4-(3,7-diorganyl-3,7-diazabicyclo[3.3.1]nonan-2-yl)butanoic acid has been accomplished starting from natural alcaloid (-)-cytisine. A five-step liquid-phase synthesis resulted in the conversion of cytisine to 7-benzyl-3-[(9H-fluoren-9-yl)methyl]-substituted acids, which were further diversified with the use of solid-phase technology on the acid-susceptible amine resins. The combinatorial library obtained is intended for a discovery of new physiologically active compounds.
New chiral amine ligands in the desymmetrization of prochiral phosphine boranes
Johansson, Magnus J.,Schwartz, Lennart,Amedjkouh, Mohamed,Kann, Nina
, p. 3531 - 3538 (2007/10/03)
P-chirogenic phosphine ligands can be prepared via desymmetrization of prochiral phosphine boranes using s-BuLi?(-)-sparteine complexes. One limitation of this method, however, has been that (+)-sparteine is not easily accessible. Herein, we show that der
