98%
921
2 minutes
20
A new class of axially chiral biaryl pyridine ligands have been rationally designed and concisely prepared in two steps by Skraup-Doebner-Miller synthesis. Their proof-of-concept application in an enantioselective aza-Friedel-Crafts reaction between 2-methylindoles and isatin -Boc ketimines has been evaluated. Specifically partnered with AgOTf, the new ligands effectively catalysed the reaction with excellent enantioselectivities (up to 96% ee) and 71-94% yields, and a series of multifunctional chiral 3-indolyl 3-amino-oxindoles were successfully obtained. Compared with other noble metals and chiral ligands, this Ag(I)-B1 partner is highly stable, cost-effective, facile and easily available. This work has successfully demonstrated the good performance of a new kind of axially biaryl quinoline ligands and is the first example of a silver-catalysed enantioselective aza-Friedel-Crafts reaction between 2-methylindoles and isatin -Boc ketimines, and has thus enriched the application of silver salts in asymmetric catalysis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d5ob00231a | DOI Listing |
J Org Chem
August 2025
Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China.
A highly enantioselective aza-Friedel-Crafts reaction of benzothiophene-2,3-dione-derived ketimines and indoles catalyzed by BINOL-derived chiral phosphoric acid was developed for the first time. This protocol enabled the synthesis of structurally diverse enantiopure hybrid 3-indolylmethanamine-benzothiophenes featuring a chiral quaternary carbon center adjacent to both N and S atoms, achieving high yields and high to excellent enantioselectivities (up to 99% yield and 99% ee). The reaction exhibits broad substrate scope, high reactivity, simple operation, and mild conditions.
View Article and Find Full Text PDFOrg Biomol Chem
May 2025
Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China.
The functionalized 11-amino-indeno[1,2-]quinoxaline scaffold is a pivotal structural motif in diverse bioactive compounds. In this study, we developed a chiral phosphoric acid catalysed enantioselective aza-Friedel-Crafts reaction between indeno[1,2-]quinoxalin-11-imines and indoles. This methodology enables the synthesis of chiral hybrid architectures incorporating both 11-aminoindeno[1,2-]quinoxaline and indole moieties, achieving exceptional synthetic efficiency (up to 99% yield) with outstanding stereocontrol (up to 99% ee).
View Article and Find Full Text PDFOrg Biomol Chem
April 2025
Key Laboratory of Asymmetric Synthesis & Chirotechnology of Sichuan Province, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, P. R. China.
A new class of axially chiral biaryl pyridine ligands have been rationally designed and concisely prepared in two steps by Skraup-Doebner-Miller synthesis. Their proof-of-concept application in an enantioselective aza-Friedel-Crafts reaction between 2-methylindoles and isatin -Boc ketimines has been evaluated. Specifically partnered with AgOTf, the new ligands effectively catalysed the reaction with excellent enantioselectivities (up to 96% ee) and 71-94% yields, and a series of multifunctional chiral 3-indolyl 3-amino-oxindoles were successfully obtained.
View Article and Find Full Text PDFChemistry
February 2025
Department of Chemistry, University of Kaiserslautern-Landau, Erwin-Schrödinger-Str. 54, 67663, Kaiserslautern, Germany.
A highly stereoselective Brønsted-acid catalyzed synthesis of densely substituted spiroisoindolinones from enamides and 3-hydroxy-isoindolinones is described. With simple Brønsted-acids, such as para-toluene sulfonic acid, spiroisoindolinones with three contiguous stereogenic centers are formed in high yields (up to 97 %) and diastereoselectivities (up to >98 : <2 : 0 : 0 dr) under mild reaction conditions. With the use of a chiral phosphoric acid catalyst, a diastereo- and enantioselective synthesis of the corresponding spiroisoindolinones was achieved.
View Article and Find Full Text PDFJ Org Chem
November 2024
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
An efficient chiral phosphoric acid-catalyzed asymmetric aza Friedel-Crafts reaction of 3,4-dihydroisoquinolines and 1-naphthols is described. The reaction provides a general method for the synthesis of diverse chiral tetrahydroisoquinoline with 1-naphthol substituents at the C1-position in excellent yields and enantioselectivities. Based on the conducted mechanistic experiments, a plausible catalytic mechanism was proposed.
View Article and Find Full Text PDF