220926-89-6Relevant academic research and scientific papers
Pd-N-heterocyclic carbene catalyzed synthesis of piperidine alkene-alkaloids and their anti-cancer evaluation
Kankala, Shravankumar,Kankala, Ranjith Kumar,Balaboina, Ramesh,Thirukovela, Narasimha Swamy,Vadde, Ravinder,Vasam, Chandra Sekhar
, p. 1180 - 1183 (2014/03/21)
A facile synthesis of piperidine alkene-alkaloids including natural (+)-Caulophyllumine B in high yields has been developed by Heck cross-coupling reaction catalyzed by simple in situ formed palladium-N-heterocyclic carbenes (Pd-NHCs). Formation of Pd(0) nanoparticles has been noticed during the reaction course. The synthesized piperidine alkene-alkaloids were evaluated for in vitro anti-cancer activity against a panel of human tumor cell lines of lung, breast and ovarian. Several of these piperidine alkene-alkaloids were found to possess highest growth inhibition activity than the standard drug cisplatin and support the concept to modulate drug receptor interaction.
Preparation of enantiopure substituted piperidines containing 2-alkene or 2-alkyne Chains: Application to total syntheses of natural quinolizidine- alkaloids
Cheng, Guolin,Wang, Xinyan,Su, Deyong,Liu, Hui,Liu, Fei,Hu, Yuefei
supporting information; experimental part, p. 1911 - 1916 (2010/06/15)
"Chemical Equation Presented" A general method, for the preparation of enantiopure 2-alkene- or 2-alkyne-containing chain substituted piperidines was established by using nonracemic Betti base as a chiral auxiliary. The key step is that the auxiliary residue was removed by a novel base-catalyzed N-debenzylation via a formation of o-quinone methide mechanism in stead, of the traditional hydrogenolysis, by which the alkene or alkyne groups survived. By this method, ten 2-alkene- or 2-alkyne-containing chain substituted piperidines were prepared on the gram scale within a few hours. To demonstrate the efficiency of the method and the versatility of the product, total, syntheses of natural alkaloids (+)-pelletierine((-)-lasubine II, and (-)-cermizine C were achieved by using (S)-2-allyl-N-Bocpiperidine as a versatile building block.
Asymmetric syntheses of N-Boc 2-substituted pyrrolidines and piperidines by intramolecular cyclization
Serino,Stehle,Yong Sun Park,Florio,Beak
, p. 1160 - 1165 (2007/10/03)
Asymmetric lithiation-substitutions by n-BuLi/(-)-sparteine with the N- Boc-N-(3-halopropyl)allylamines 1-4 provide the N-Boc-2-alkenylpyrrolidines (S)-5, (S)-6, and (S)-7 in yields of 3193% with enantiomeric ratios (ers) from 65:35 to 90:10. These reactions are shown to involve an initial asymmetric deprotonation, but the enantiodetermining step is a subsequent asymmetric cyclization under the influence of the chiral ligand. Extension to formation of a piperidine is illustrated by reaction of N-Boc-(4- chlorobutyl)cinnamylamine (9) to afford (S)-N-Boc-2-(trans-β- styryl)piperidine ((S)-10) in 68% yield with an enantiomeric ratio (er) of 84:16. Analogous reactions with epoxide ring openings of N-Boc-N- (oxaalkenyl)benzylamines 11 and 12 afford the corresponding N-Boc-2-phenyl- 3-(hydroxymethyl)pyrrolidine (13) in 67% yield with a diastereomeric ratio (dr) of 50:50 and ers of 97:3 and 95:5 and the corresponding N-Boc-2-phenyl- 3-(hydroxymethyl)piperidine (14) in 29% yield with a dr of 86:14 and ers of 81:19 and 86:14.
