Two syntheses of 3-substituted-4-amino-[3,2-c]thienopyridines have been developed to replace the standard literature route to these compounds, which uses unattractive conditions involving azide and high temperatures. The first synthesis utilizes a Friedel-Crafts reaction as its key ring-forming step, whereas the second route relies on an unprecedented intramolecular reductive cyclization between a nitroolefin and a nitrile as its key ring-forming step. The development and optimization of each 3-substituted-4-amino-[3,2-c]thienopyridine synthesis is discussed and a comparison of the routes is presented.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jo9003772 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.
We present a six-step cascade that converts 1,3-distyrylbenzenes (-stilbenes) into nonsymmetric pyrenes in 40-60% yields. This sequence merges photochemical steps, ,-alkene isomerization, a 6π photochemical electrocyclization (Mallory photocyclization); the new bay region cyclization, with two radical iodine-mediated aromatization steps; and an optional aryl migration. This work illustrates how the inherent challenges of engineering excited state reactivity can be addressed by logical design.
View Article and Find Full Text PDFCytoskeleton (Hoboken)
December 2024
GN Ramachandran Protein Center, CSIR Institute of Microbial Technology, Chandigarh, India.
Z-ring formation by FtsZ, the master assembler of the divisome, is a key step in bacterial cell division. Membrane anchoring of the Z-ring requires the assistance of dedicated Z-ring binding proteins, such as SepF and FtsA. SepF participates in bundling and membrane anchoring of FtsZ in gram-positive bacteria.
View Article and Find Full Text PDFJ Am Chem Soc
September 2024
Department of Chemistry, State Key Lab of Molecular Engineering of Polymers, and Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China.
A confined space preorganizes substrates, which substantially changes their chemical reactivity and selectivity; however, the performance as a reaction vessel is hampered by insensitivity to environmental changes. Here, we show a dynamic confined space formed by substrate grasping of an amphiphilic host with branched aromatic arms as an active molecular gripper capable of performing substrate grasping, macrocyclization, and product release acting as a macrocycle synthesizer. The confined reaction space is formed by the substrate grasping of the molecular gripper, which is further stabilized by gel formation.
View Article and Find Full Text PDFBeilstein J Org Chem
August 2024
Heinrich-Heine-Universität Düsseldorf, Math.-Nat. Fakultät, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
Pyrazoles are rarely found in nature but are traditionally used in the agrochemical and pharmaceutical industries, while other areas of use are also actively developing. However, they have also found numerous other applications. The search for new and efficient syntheses of these heterocycles is therefore highly relevant.
View Article and Find Full Text PDFChem Sci
August 2024
School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Beijing Frontier Research Center for Biological Structure, Tsinghua University Beijing 100084 China
The Pictet-Spengler type condensation of tryptamine derivatives and aldehydes or ketones is a classic reaction, and has been previously applied to assemble indole-annulated 5-, 6- and 8-membered heterocyclic rings. In this work, we further expand the synthetic scope of this reaction to the 7-membered azepino[4,5-]indole skeleton through the direct C-H functionalization of 2-alkyl tryptamines, in which the non-activated methylene group participates in a 7-membered ring formation with aldehydes. By combining this unprecedented ring-forming process with a second C-H olefination at the same carbon, the concise total synthesis of natural products ngouniensines is achieved, demonstrating the synthetic potential of the developed chemistry in simplifying retrosynthetic disconnections.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!