33948-35-5Relevant articles and documents
Total Synthesis of Isodaphlongamine H: A Possible Biogenetic Conundrum
Chattopadhyay, Amit Kumar,Ly, Vu Linh,Jakkepally, Shashidhar,Berger, Gilles,Hanessian, Stephen
, p. 2577 - 2581 (2016)
Herein we describe the first synthetic efforts toward the total synthesis of isodaphlongamine H, a calyciphylline B-type alkaloid. The strategy employs a chemoenzymatic process for the preparation of a functionalized cyclopentanol with a quaternary center. This molecule is elaborated to form an enantiopure 1-aza-perhydrocyclopentalene core, representing rings A and E of all calyciphylline B-type alkaloids. Further transformations involve the formation of a cyclic enaminone, 1,4-conjugate addition with a cyclopentenyl subunit, and intramolecular aldol cyclization to achieve a pentacyclic intermediate, ultimately forming isodaphlongamine H in a total of 24 steps from the commercially available compound 2-carbethoxycyclopentanone. Isodaphlongamine H exhibits promising inhibitory activity against a panel of human cancer cell lines. The missing link? A concise and highly convergent total synthesis of isodaphlongamine H was accomplished in 24 linear steps. The molecule exhibited promising inhibitory activity against a panel of human cancer cell lines. PCC=pyridinium chlorochromate.
Rhodium-Catalyzed [4+3] Cycloaddition to Furans: Direct Access to Functionalized Bicyclo[5.3.0]decane Derivatives
Krainz, Tanja,Chow, Sharon,Korica, Natasa,Bernhardt, Paul V.,Boyle, Glen M.,Parsons, Peter G.,Davies, Huw M. L.,Williams, Craig M.
, p. 41 - 44 (2016)
An efficient method to directly access the bicyclo[5.3.0]decane core was achieved by rhodium-catalyzed reaction of a novel donor-acceptor cyclopentenyl diazocarboxylate with a variety of furans. As this motif is commonly found within bioactive antitumor natural products, selected systems were further manipulated and evaluated against cancer cell lines sensitive to protein kinase C (PKC) activation. A cyclic donor-acceptor diazo compound was synthesized for the first time, facilitating direct access to the bicyclo[5.3.0]decane motif, which is commonly seen in a number of prominent natural products active against cancer. Some examples were evaluated against various PKC cancer cell lines.
Enantioselective Synthesis of All-Carbon Quaternary Centers Structurally Related to Amaryllidaceae Alkaloids
Miku?ek, Ji?í,Jansa, Petr,Jagtap, Pratap R.,Va?í?ek, Tomá?,Císa?ová, Ivana,Matou?ová, Eli?ka
, p. 10069 - 10072 (2018)
Enantioselective synthesis of all-carbon quaternary centers remains a considerable challenge for synthetic organic chemists. Here, we report a two-step protocol to synthesize such centers including tandem cyclization/Suzuki cross-coupling followed by halocarbocyclization. During this process, two rings, three new C?C bonds and a stereochemically defined all-carbon quaternary center are formed. The absolute configuration of this center is controlled by the stereochemistry of the adjacent stereocenter, which derives from an appropriate enantioenriched starting material. Using this method, we synthesized polycyclic compounds structurally similar to Amaryllidaceae alkaloids in high enantiomeric excesses. Because these products resemble naturally occurring compounds, our protocol can be used to synthesize various potentially bioactive compounds.
The development and scope of a versatile tandem Stille-oxa-electrocyclization reaction
Tambar, Uttam K.,Kano, Taichi,Zepernick, John F.,Stoltz, Brian M.
, p. 345 - 350 (2007)
A palladium-catalyzed tandem Stille-oxa-electrocyclization reaction has been developed for the convergent preparation of highly substituted polycyclic pyran systems. The strategy presented in this letter is an alternative to the known methods for construc
Tethered Counterion-Directed Catalysis: Merging the Chiral Ion-Pairing and Bifunctional Ligand Strategies in Enantioselective Gold(I) Catalysis
Frison, Gilles,Guinchard, Xavier,Marinetti, Angela,Retailleau, Pascal,Smal, Vitalii,Voituriez, Arnaud,Zhang, Zhenhao
supporting information, p. 3797 - 3805 (2020/03/10)
Tethering a metal complex to its phosphate counterion via a phosphine ligand enables a new strategy in asymmetric counteranion-directed catalysis (ACDC). A straightforward, scalable synthetic route gives access to the gold(I) complex of a phosphine displaying a chiral phosphoric acid function. The complex generates a catalytically active species with an unprecedented intramolecular relationship between the cationic Au(I) center and the phosphate counterion. The benefits of tethering the two functions of the catalyst are demonstrated here in a tandem cycloisomerization/nucleophilic addition reaction, by attaining high enantioselectivity levels (up to 97% ee) at an unusually low 0.2 mol % catalyst loading. Remarkably, the method is also compatible with a silver-free protocol.
