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/jo960848z | DOI Listing |
Adv Respir Med
December 2024
Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm University, 89075 Ulm, Germany.
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 PDFCommun Chem
December 2024
Department of Chemistry, The University of Manchester, Manchester, UK.
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 PDFEur 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 PDFPest Manag Sci
December 2024
School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China.
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 PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!