Keteniminium Salts as Key Intermediates for the Efficient Synthesis of 3‐Amino‐Indoles and ‐Benzofurans

Herein, we describe a high yielding approach towards the synthesis of 3‐amino‐indoles and ‐benzofurans through 6π‐electrocyclization. This was made possible by taking advantage of the high reactivity of keteniminium salts, formed in‐situ by treating with triflic anhydride and 2‐fluoropyridine amides...

Full description

Saved in:
Bibliographic Details
Published in:Helvetica chimica acta 2020-01, Vol.103 (1), p.n/a
Main Authors: Dagoneau, Dylan, Kolleth, Amandine, Quinodoz, Pierre, Tanriver, Gamze, Catak, Saron, Lumbroso, Alexandre, Sulzer‐Mossé, Sarah, De Mesmaeker, Alain
Format: Article
Language:English
Subjects:
Amides
aminobenzofuran
aminoindole
Aniline
electrocyclic reactions
Functional groups
Indoles
Intermediates
keteniminium
Salts
Synthesis
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Herein, we describe a high yielding approach towards the synthesis of 3‐amino‐indoles and ‐benzofurans through 6π‐electrocyclization. This was made possible by taking advantage of the high reactivity of keteniminium salts, formed in‐situ by treating with triflic anhydride and 2‐fluoropyridine amides bearing at the α‐position either an aniline or a phenoxy moiety. These mild conditions, on top of furnishing rapidly the 3‐aminobenzoheteroles, allow the tolerance of various functional groups. Control experiments were carried out to highlight that the keteniminium is, indeed, in most cases, the reactive intermediate and conformational preferences of such species were investigated through a DFT study.
ISSN:0018-019X
1522-2675
DOI:10.1002/hlca.201900217