Journal ArticleDOI
Domino Reactions - One-pot Preparation of Fluoreno[2,3,4-ij]isoquinoline Derivatives From Conjugated Ketene Imines
TLDR
Iminophosphoranes 4, derived from ethyl alpha-azido-2-(allyloxy)-3-methoxycinnamates react with ketenes to give the corresponding ketene imines to give isoquinoline derivatives 7 and/or the previously unknown fluoreno[2,3,4-ij]isoquinolines 9 in moderate yields.Abstract:
Iminophosphoranes 4, derived from ethyl alpha-azido-2-(allyloxy)-3-methoxycinnamates, react with ketenes to give the corresponding ketene imines, which by thermal treatment at 150-160-degrees-C undergo a consecutive electrocyclic ring closure/Claisen rearrangement/second ring closure/double aromatization process to give isoquinoline derivatives 7 and/or the previously unknown fluoreno[2,3,4-ij]isoquinolines 9 in moderate yields. Similarly, iminophosphoranes 14 derived from ethyl alpha-azido-2,3-disubstituted-4-(allyloxy)cinnamates reacted with diphenyl ketene to give the intermediate ketene imines, which at 150-160-degrees-C undergo a cascade of pericyclic reactions to give the isoquinolines 15 and the pentacyclic compounds 16 in moderate yields.read more
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Recent Highlights in Ketenimine Chemistry
TL;DR: In this article, a review of recent developments in the chemistry of ketenimines is presented, demonstrating that heterocumulenes of this class are versatile reactive intermediates in the synthesis of nitrogenated heterocycles.
Journal ArticleDOI
Intramolecular addition of benzylic radicals onto ketenimines. Synthesis of 2-alkylindoles
TL;DR: The intramolecular addition of benzylic radicals, generated from xanthates, onto the central carbon of a ketenimine function with its N atom linked to the ortho position of the aromatic ring provides a novel radical-mediated synthesis of 2-alkylindoles.
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Tandem 1,5‐Hydride Shift/6π Electrocyclization of Ketenimines and Carbodiimides Substituted with Cyclic Acetal and Dithioacetal Functions: Experiments and Computations
TL;DR: In this paper, N-Aryl ketenimines bearing five-and six-membered cyclic acetal functions were converted into quinazolines through a tandem sequence consisting of a [1,5]-H shift followed by a 6π electrocyclic ring closure.
Journal ArticleDOI
First radical addition onto ketenimines: a novel synthesis of indoles
TL;DR: In this article, a non-chain process based on the intramolecular addition of benzylic radicals onto the central carbon atom of a ketenimine function, resulting in a 5-exo-dig cyclization is described.
Journal ArticleDOI
Intramolecular 2 + 2 cycloaddition of ketenimines with imines
TL;DR: In this paper, the intramolecular cycloaddition reaction of ketenimines with imines has been used to obtain [2,1-b]quinazolines.