Pummerer cyclization of β-aminoethyl sulfoxide 6 was effectively achieved using TFAA-TFA in toluene at 80 °C. The cyclized product 7 was then converted to the alkaloid deethylibophyllidine. The required pyrrolo[3,2-c]carbazole 6 was prepared in five steps from 4-methoxyphenethylamine.
使用TFAA-TFA在80°C的甲苯中可有效实现β-氨基乙基亚砜6的Pummerer环化。然后将环化的产物7转化为生物碱脱乙基核糖胞苷。由4-甲氧基苯乙胺分五个步骤制备所需的吡咯并[3,2- c ]咔唑6。
Total Synthesis of (±)-Deethylibophyllidine: Studies of a Fischer Indolization Route and a Successful Approach via a Pummerer Rearrangement/Thionium Ion-Mediated Indole Cyclization
作者:Josep Bonjoch、Juanlo Catena、Nativitat Valls
DOI:10.1021/jo960848z
日期:1996.1.1
derivatives, the regioselective Fischer indolization to obtain octahydropyrrolo[3,2-c]carbazoles, and the tandem process consisting of Pummerer rearrangement upon a beta-amino sulfoxide and thionium ion cyclization upon a beta-indole position of a 2,3-disubstituted indole to generate the quaternary spiro center. Attempts to effect the construction of the pentacyclic framework by means of Fischer indolization
Cyclizations of a bicyclic amine via an intramolecular Heck reaction followed by an oxidation reaction generated a tetracyclic spirocyclohexadione. From this useful intermediate, different crinine alkaloids such as crinine, buphanisine, flexinine, and augustine could be synthesized. Dienol/benzene or dienone/phenol rearrangement of this tetracyclic spirodienone afforded apogalanthamine analogs.
An Efficient Palladium Mediated Synthesis of (±)-γ-Lycorane
作者:Hongbin Zhang、Zhihui Shao、Jingbo Chen、Rong Huang、Chenying Wang、Liang Li
DOI:10.1055/s-2003-42053
日期:——
An intramolecular approach incorporating a Michael addition followed by a palladium-mediated arylation of ketone towards the synthesis of Amaryllidaceae alkaloid (±)-γ-lycorane was reported.
Synthesis and Pharmacological Evaluation of DHβE Analogues as Neuronal Nicotinic Acetylcholine Receptor Antagonists
作者:Tue Heesgaard Jepsen、Anders A. Jensen、Mads Henrik Lund、Emil Glibstrup、Jesper Langgaard Kristensen
DOI:10.1021/ml500094c
日期:2014.7.10
the α4β2-subtype of the nicotinicacetylcholinereceptors (nAChRs). Guided by an X-ray structure of DHβE in complex with an ACh binding protein, we detail the design, synthesis, and pharmacological characterization of a series of DHβE analogues in which two of the four rings in the natural product has been excluded. We found that the direct analogue of DHβE maintains affinity for the α4β2-subtype, but