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
Cationic 1-substituted-dicarbonyl(η5-4-methoxycyclohexadienyl)-(triphenylphosphine)iron complexes 10 from a new class of highly functionalised iron complexes which have never been described. They were obtained from neutral 1-substituted(η4-4-methoxy-1,3-cyclohexadiene)Fe(CO)2PPh3 iron complexes 9, prepared by ligand exchange reaction under improved experimental conditions. A quaternary carbon was formed
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.