Benzannelated heterocycles such as indoles and indazoles are prominent structural motifs found in natural products, pharmaceuticals and agrochemicals. For their synthesis, chemists traditionally either functionalize commercially available heterocycles or resort to transformations that make use of benzene-derived building blocks. Here, we report a powerful cascade reaction that enables the de novo construction of variously substituted indoles, indazoles, benzofurans and benzothiophenes from readily available bicyclo[3.1.0]hexan-2-ones. The transformation can be conducted under mild, non-anhydrous conditions. For the synthesis of indoles, mechanistic studies revealed that the electrocyclic ring-opening of the bicyclic ring-system and aromatization precedes the 3,3-sigmatropic rearrangement.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821223 | PMC |
| http://dx.doi.org/10.1002/chem.201705662 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effects of benzoheterocyclic annelation on the -indacene core: a computational analysis.
Chem Sci
January 2025
Schulich Faculty of Chemistry and the Resnick Sustainability Center for Catalysis, Technion - Israel Institute of Technology Haifa 32000 Israel
Article Synopsis
- * The study uses computational methods to investigate how heteroatoms and heterocyclic fusion influence antiaromaticity in -indacene, revealing that both factors significantly impact stability, with the position of substitution being crucial.
- * The research highlights that while heteroatom effects are stronger, heterocycle fusion still plays a role, and understanding these interactions can help design more stable antiaromatic compounds for electronic applications.
De Novo Synthesis of Benzannelated Heterocycles.
Chemistry
January 2018
Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria.
Benzannelated heterocycles such as indoles and indazoles are prominent structural motifs found in natural products, pharmaceuticals and agrochemicals. For their synthesis, chemists traditionally either functionalize commercially available heterocycles or resort to transformations that make use of benzene-derived building blocks. Here, we report a powerful cascade reaction that enables the de novo construction of variously substituted indoles, indazoles, benzofurans and benzothiophenes from readily available bicyclo[3.
View Article and Find Full Text PDFSolid Phase Synthesis of (Benzannelated) Six-Membered Heterocycles via Cyclative Cleavage of Resin-Bound Pseudo-Oxazolones.
Org Lett
August 2016
Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
A solid supported procedure for the synthesis of benzoxazinones, dihydropyrazinones, quinoxalinones, and dihydrooxazinones using immobilized oxazolones in combination with difunctional nucleophiles as cleavage agent is presented. The scope of the novel method has been demonstrated through subsequent modification of the parent oxazolone scaffold on solid supports using conversions with electrophiles or CuAAC reactions to give functionalized pyrazin-2-ones. The described method allows the synthesis of the target heterocycles in good yields via three to five steps on solid phases with only one chromatographic purification step.
View Article and Find Full Text PDFA new three-carbon synthon for efficient synthesis of benzannelated and 1-(2-arylethenyl) heterocycles.
J Org Chem
November 2000
Center for Heterocyclic Compounds, University of Florida, Department of Chemistry, Gainesville, Florida 32611-7200, Bristol Myers Squibb Co., Pharmaceutical Research Institute, Route 206 & Provinceline Road, Princeton, New Jersey 08563, and Bristol.
The novel three-carbon synthon 1-(1H-1,2, 3-benzotriazol-1-yl)-3-chloroacetone for the synthesis of benzothiazoles, pyrido[1,2-a]indoles, and styryl-substituted indolizines and imidazo[1,2-a]pyridines is reported. The proposed routes are a general and efficient approach for heterocyclizations followed by benzannelations or attachment of arylethenyl pharmacophores.
View Article and Find Full Text PDFWant 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!