144409-60-9Relevant academic research and scientific papers
α-C-H Bond Functionalization of Unprotected Alicyclic Amines: Lewis-Acid-Promoted Addition of Enolates to Transient Imines
Kim, Jae Hyun,Paul, Anirudra,Ghiviriga, Ion,Seidel, Daniel
supporting information, p. 797 - 801 (2021/02/06)
Enolizable cyclic imines, obtained in situ from their corresponding lithium amides by oxidation with simple ketone oxidants, are readily alkylated with a range of enolates to provide mono- and polycyclic β-aminoketones in a single operation, including the natural product (±)-myrtine. Nitrile anions also serve as competent nucleophiles in these transformations, which are promoted by BF3 etherate. β-Aminoesters derived from ester enolates can be converted to the corresponding β-lactams.
Strategies for the Asymmetric Construction of Pelletierine and its Use in the Synthesis of Sedridine, Myrtine, and Lasubine
Zaidan, Raed K.,Evans, Paul
, p. 5354 - 5367 (2019/06/25)
Three methods for the asymmetric synthesis of both enantiomers of pelletierine 6 are reported. Bella's proline-based Mannich process gave (R)- and (S)-Cbz-protected 6 in good yields from Δ1-piperideine 14 and in reasonable enantiomeric excess (74–80 % ee). An intramolecular aza-Michael, cinchona-based, organocatalytic method is also reported. With commercially available 9-amino quinine (24a) and quinidine (24b) catalysts, Cbz-protected α,β-unsaturated ketone 23 also gave (R)- and (S)-Cbz-protected 6 in good yields and enantiomeric excess (90–99 % ee). This material was used to synthesize both optically active forms of deoxyhalofuginone (26), an analogue of febrifugine which is of interest as an anti-fibrotic agent. Finally, a resolution of racemic pelletierine using (R)- and (S)-mandelic acid 27 is reported. This scalable method gave both enantiomers of Cbz- and Boc-protected 6 in excellent enantiomeric excess (≥ 99 %). Both highly enantioenriched forms of 6 (obtained from the resolution study) were used to synthesize several alkaloids. Firstly, (–)-(S)-Cbz-protected pelletierine 17 was used to prepare naturally occurring sedridine (32) and its epimer allosedridine (8). Then the preparation of both enantiomers of the quinolizidine myrtine (33) by an olefination-intramolecular aza-Michael sequence is reported. Finally, the synthesis of the epimeric quinolizidine alkaloids, lasubine I (34) and lasubine II (35), from (+)- and (–)-Boc-protected pelletierine (29) respectively, is discussed.
Catalytic Dearomatization Approach to Quinolizidine Alkaloids: Five Step Total Synthesis of (±)-Lasubine II
James, Michael J.,Grant, Niall D.,O'Brien, Peter,Taylor, Richard J. K.,Unsworth, William P.
, p. 6256 - 6259 (2016/12/23)
A series of high-yielding silver(I)-catalyzed cyclization reactions of pyridine-, isoquinoline-, and pyrazine-ynones are described. The operationally simple and mild reaction conditions are a significant improvement over previously reported thermal cycliz
A method for synthesizing compound of [...]
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Paragraph 0033; 0034, (2017/03/28)
The invention relates to quinolizidine compounds, particularly a synthesis method of a quinolizidine ketone compound. The method comprises the following steps: carrying out aza Diels-Alder reaction on a compound 1 chloroacylbutyl amine in a halohydrocarbon solvent or alcohol solvent at 0-30 DEG C under the actions of fluoroform sulfonic anhydride, silane, organic base and diolefin, carrying out hydrochloric acid treatment, extracting, drying, concentrating, and purifying to obtain a compound 2 chloro-2,3-dihydro-4-pyridone; carrying out iodo reaction on the compound 2 chloro-2,3-dihydro-4-pyridone in a ketone solvent at 30-90 DEG C under the action of an iodate, extracting, drying, concentrating and purifying to obtain a compound 3-iodo-2,3-dihydro-4-pyridone; and reacting the compound 3 in a halohydrocarbon solvent at 60-100 DEG C under the actions of an initiator and a reducer, concentrating, and purifying to obtain the compound 4 quinolizidine ketone compound.
Synthetic applications of sulfur-substituted indolizidines and quinolizidines
Chou, Shang-Shing P.,Chung, Yi-Ching,Chen, Po-An,Chiang, Shan-Lun,Wu, Chien-Jung
experimental part, p. 692 - 695 (2011/03/20)
Starting from the sulfur-substituted indolizidines and quinolizidines, a few useful synthetic transformations have been developed and the synthesis of some natural products including indolizidine 209D, epimyrtine, lasubine II, 8a-epi-dendroprimine, and 5-
Rhodium-catalyzed intramolecular conjugate addition of vinylstannanes to?dihydro-4-pyridones: a simple method for stereoselective construction of 1-azabicyclic alkaloids
Furman, Bart?omiej,Lipner, Grzegorz
, p. 3464 - 3470 (2008/09/20)
A straightforward route for the stereoselective synthesis of unsaturated quinolizidines and related higher homologs has been developed. Our results revealed that the rhodium complex [RhCl(cod)]2 is an effective catalyst for the intramolecular c
A synthesis of the quinolizidine alkaloids (±)-lasubine I and (±)-lasubine II
Bardot, Valérie,Gardette, Daniel,Gelas-Mialhe, Yvonne,Gramain, Jean-Claude,Remuson, Roland
, p. 507 - 518 (2007/10/03)
A total synthesis of (±)-lasubine I and (±)-lasubine II has been achieved in six steps from a β-hydroxyallylsilane synthon using intramolecular cyclization of allylsilane on N-acyliminium ion as a key step.
Asymmetric synthesis of quinolizidine alkaloids (-)-lasubine I, (-)- lasubine II and (+)-subcosine II
Chalard, Pierre,Remuson, Roland,Gelas-Mialhe, Yvonne,Gramain, Jean-Claude
, p. 4361 - 4368 (2007/10/03)
The enantioselective synthesis of (-)-lasubine I 1 and the first asymmetric synthesis of (-)-lasubine II 2 and (+)-subcosine II 3 is described. The key step is the intramolecular cyclization of N-acyliminium ion 4 which is derived from (S)-aminoester 6.
One-pot preparation of quinolizidin-2-one and indolizidin-7-one ring systems. Concise total synthesis of (±)-myrtine, (±)-lasubine II, and (-)-indolizidine 223AB
Pilli,Carlos Dias,Maldaner
, p. 717 - 722 (2007/10/02)
A highly efficient approach to the quinolizidine alkaloids (±)-myrtine (4) and (±)-lasubine II (5) and to the indolizidine alkaloid (-)-indolizidine 223AB (6) is described. The preparation of quinolizidin-2-ones 4/4a and 11b/12b and indolizidin-7-ones 16/
Tandem N-acyliminium-Michael addition reaction. An efficient total synthesis of the quinolizidine alkaloids (+/-)-myrtine and (+/-)-lasubine II
Pilli,Dias,Maldaner
, p. 2729 - 2732 (2007/10/02)
A short and efficient preparation of the quinolizidine alkaloids (±)-lasubine II (1) and (±)-myrtine (2) is described featuring the tandem N-acyliminium ion-Michael addition of 2-trimethylsilyloxy butadienes to ethoxycarbamate 4 promoted by TMSOTf.
