18161-94-9Relevant articles and documents
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
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
