A new electron-deficient chiral triazolium salt has been shown to catalyze the formation of quaternary stereocenters by an asymmetric intramolecular Stetter reaction. Pentafluorophenyl substitution on an aminoindanol-derived catalyst affords tertiary ether, thioether, and quaternary stereocenters in typically greater than 90% ee and very good chemical yield. Aromatic and aliphatic aldehydes are equally competent substrates for this reaction. The reaction proceeds at room temperature under mild conditions to provide quaternary stereocenters with functional group relationships that are particularly difficult to access by other methods.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja047644h | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Synthesis of 4-hydroxypiperidines containing a quaternary stereocenter by aza-Prins cyclization.
Org Biomol Chem
January 2025
Univ Rennes, CNRS, ISCR - UMR 6226, F-35000 Rennes, France.
A straightforward and highly diastereoselective synthesis of -4-hydroxypiperidines is presented. This method allows access to C2 and C4 substituted piperidines, bearing a tetrasubstituted carbon stereocenter at C4. -Disubstituted homoallylic amines and ketoaldehydes as carbonyl partners have been rarely used in aza-Prins cyclizations, expanding the scope of this reaction.
View Article and Find Full Text PDFReversed Allylation of 3-Alkenyl Indoles Using Allyl Boronic Acids: Access to Tryptamine Based Alkaloids.
Chemistry
January 2025
Department of Chemistry, Indian Institute of Technology Kharagpur Kharagpur 721302, West Bengal, India.
All-carbon quaternary and tertiary stereocenters connected at the C2-position of functionalizable C3-alkylated indole nucleus are commonly occurring frameworks found in many indole alkaloids of medicinal importance. Their direct access is scarcely reported, a long-standing problem, and developing a unique yet simple method can pave the pathway to an entirely different retrosynthetic route for the total synthesis of these alkaloids. Herein, this problem is addressed by developing an unprecedented branch-selective allylation strategy employing a broad range of structurally and electronically different 3-alkenyl-indoles and allylboronic acids.
View Article and Find Full Text PDFConstruction of benzimidazole- and indole-fused azabicyclo[3.1.0]hexanes bearing a cyano-containing quaternary center from vinylsulfonium salts through sequential [3 + 2]/[2 + 1] cyclization.
Org Biomol Chem
January 2025
Department of Chemistry, College of Sciences, Tianjin University of Science and Technology, Tianjin 300457, People's Republic of China.
A sequential [3 + 2]/[2 + 1] annulation reactions of benzimidazole- and indole-derived acrylonitriles with vinylsulfonium salts have been developed for the first time, and shown to provide in yields of 32 to 98% a series of azabicyclo[3.1.0]hexanes containing each a cyano-substituted tetrasubstituted carbon stereocenter with >20 : 1 dr.
View Article and Find Full Text PDFSynthesis of Rigid Stepladder Polymers Scandium-Catalyzed Polyspiroannulation of Quinoline with Alkyne.
J Am Chem Soc
January 2025
Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Article Synopsis
- The study focuses on the development of a new type of rigid, three-dimensional polymers known as stepladder polymers, utilizing spirodihydroquinoline structures.
- These polymers are created through a reaction facilitated by a scandium catalyst that activates specific chemical bonds, allowing for the formation of complex structures from quinoline and alkyne compounds.
- The resulting polymers have increased thermal stability and porosity after undergoing a treatment that adds a methyl group to their nitrogen-containing functional groups.
Copper-Catalyzed Asymmetric Nucleophilic Opening of 1,1,2,2-Tetrasubstituted Donor-Acceptor Cyclopropanes for the Synthesis of α-Tertiary Amines.
J Am Chem Soc
January 2025
State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China.
Catalytic asymmetric transformation of donor-acceptor cyclopropanes (DACs) has been proven to be a highly valuable and robust strategy to construct diverse types of enantioenriched molecules. However, the use of 1,1,2,2-tetrasubstituted DACs to form products bearing quaternary stereocenters remains a long-term unsolved challenge. Here, we report the copper-catalyzed asymmetric aminative ring opening of tetrasubstituted alkynyl DACs that delivers a myriad of α-tertiary amines with high levels of enantioselectivities.
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!