The total synthesis of (+/-)-deethylibophyllidine is described, proceeding in eight steps from 4-(methoxyphenyl)ethylamine in 5% overall yield (Scheme 6). In terms of sequential annulation, the strategy involves the following operations: E --> DE --> ABDE --> ABCDE (Scheme 1). The key steps in the synthesis are the stereoselective formation of octahydroindol-6-ones by acid treatment of dihydroanisole 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 of the octahydropyrrolo[3,2,1-hi]indol-6-one resulted in failure (Scheme 2).

Download full-text PDF

Source
http://dx.doi.org/10.1021/jo960848zDOI Listing

Publication Analysis

Top Keywords

fischer indolization
12
total synthesis
8
synthesis +/--deethylibophyllidine
8
+/--deethylibophyllidine studies
4
studies fischer
4
indolization route
4
route successful
4
successful approach
4
approach pummerer
4
pummerer rearrangement/thionium
4

Similar Publications

Elexacaftor/Tezacaftor/Ivacaftor (ETI) is a CFTR modulator therapy approved for people with cystic fibrosis (pwCF) who have at least one phe508del mutation. However, its approval in the European Union (EU) for pwCF with non-phe508del mutations is lacking, because data on treatment response in this subgroup are scarce. This retrospective observational study evaluated six pwCF (ages 6 to 66) with responsive CFTR mutations (M1101K, R347P, 2789+5G>A, G551D) undergoing off-label ETI therapy.

View Article and Find Full Text PDF

Energy-efficient and deep-blue organic light-emitting diode (OLED) with long operating stability remains a key challenge to enable a disruptive change in OLED display and lighting technology. Part of the challenge is associated with a very narrow choice of the robust host materials having over 3 eV triplet energy level to facilitate efficient deep-blue emission and deliver excellent performance in the OLED device. Here we show the molecular design of new 1,3,5-oxadiazines (NON)-host materials with high triplet energy over 3.

View Article and Find Full Text PDF

Design, synthesis, and biological evaluation of steroidal indole derivatives as membrane-targeting antibacterial candidates.

Eur J Med Chem

February 2025

Department of Life Sciences, Changzhi University, Changzhi, 046011, Shanxi, China; Department of Chemistry, Changzhi University, Changzhi, 046011, Shanxi, China. Electronic address:

Rational modification of natural products plays a key role in drug discovery. Herein, a series of steroidal indole derivatives containing various substituents and steroidal skeletons were designed and synthesized with classical Fischer indole synthesis as a key step in an efficient synthetic route for the first time. The in vitro antibacterial activity of all the synthesized derivatives was evaluated against four Gram-positive strains including three Methicillin-Resistant Staphylococcus aureus.

View Article and Find Full Text PDF
Article Synopsis
  • Plant pathogenic bacteria and fungi significantly harm crops, leading to serious economic losses, prompting the search for effective alternatives to traditional antibiotics and fungicides.
  • This study designed and synthesized new chemical compounds based on tetrahydrocarbazole (THCz) alkaloids and evaluated their antimicrobial properties against various harmful plant pathogens.
  • Among the synthesized derivatives, compound KZa-17 showed promising antibacterial activity, outperforming traditional control drugs and demonstrating the potential for use in developing more effective agricultural treatments.
View Article and Find Full Text PDF

Synthesis of drimanyl indole fragments of drimentine alkaloids and their antibacterial activities.

Bioorg Med Chem Lett

February 2025

College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China. Electronic address:

Two types of drimanyl indole fragments of drimentine alkaloids were synthesized and evaluated their in vitro antibacterial activities using minimum inhibitory concentration. Analysis of structure-activity relationship against Ralstonia solanacearum revealed that fragment I exhibited superior inhibitory activity compared to fragment II. Notably, free NH of the indole motif was essential for antibacterial activity, while COH of the drimane skeleton was beneficial for enhancing the inhibitory effect.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!