Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[: B] [1,5]oxazocine heterocycles

Ramani Gurubrahamam; Koppanathi Nagaraju; Kwunmin Chen

doi:10.1039/c8cc02565g

Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[: B] [1,5]oxazocine heterocycles

Ramani Gurubrahamam, Koppanathi Nagaraju, Kwunmin Chen^*

^*Corresponding author for this work

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

16 Citations (Scopus)

Abstract

Metal-free addition of salicylhydrazones to electron deficient internal alkynes catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles was achieved. The demonstrated protocol proceeds through an o-quinone methide formation, aza-Michael addition, stereoselective protonation, enamine promoted aromatization, O,O-acetalization and O,N-aminalization sequence to provide privileged heterocycles in good yields with high diastereoselectivities.

Original language	English
Pages (from-to)	6048-6051
Number of pages	4
Journal	Chemical Communications
Volume	54
Issue number	47
DOIs	https://doi.org/10.1039/c8cc02565g
Publication status	Published - 2018

ASJC Scopus subject areas

Catalysis
Electronic, Optical and Magnetic Materials
Ceramics and Composites
General Chemistry
Surfaces, Coatings and Films
Metals and Alloys
Materials Chemistry

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10.1039/c8cc02565g

Cite this

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title = "Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[: B] [1,5]oxazocine heterocycles",

abstract = "Metal-free addition of salicylhydrazones to electron deficient internal alkynes catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles was achieved. The demonstrated protocol proceeds through an o-quinone methide formation, aza-Michael addition, stereoselective protonation, enamine promoted aromatization, O,O-acetalization and O,N-aminalization sequence to provide privileged heterocycles in good yields with high diastereoselectivities.",

author = "Ramani Gurubrahamam and Koppanathi Nagaraju and Kwunmin Chen",

note = "Publisher Copyright: {\textcopyright} 2018 The Royal Society of Chemistry.",

year = "2018",

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AU - Gurubrahamam, Ramani

AU - Nagaraju, Koppanathi

AU - Chen, Kwunmin

PY - 2018

Y1 - 2018

N2 - Metal-free addition of salicylhydrazones to electron deficient internal alkynes catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles was achieved. The demonstrated protocol proceeds through an o-quinone methide formation, aza-Michael addition, stereoselective protonation, enamine promoted aromatization, O,O-acetalization and O,N-aminalization sequence to provide privileged heterocycles in good yields with high diastereoselectivities.

AB - Metal-free addition of salicylhydrazones to electron deficient internal alkynes catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles was achieved. The demonstrated protocol proceeds through an o-quinone methide formation, aza-Michael addition, stereoselective protonation, enamine promoted aromatization, O,O-acetalization and O,N-aminalization sequence to provide privileged heterocycles in good yields with high diastereoselectivities.

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Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[: B] [1,5]oxazocine heterocycles

Abstract

ASJC Scopus subject areas

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CCDC 1819727: Experimental Crystal Structure Determination

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Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[: B] [1,5]oxazocine heterocycles

Abstract

ASJC Scopus subject areas

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Datasets

CCDC 1819727: Experimental Crystal Structure Determination

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