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[3+2] cycloadditions of n-protected ‘(s)-diazoproline’ with selected acetylenes


Mloston, Grzegorz; Pipiak, Paulina; Heimgartner, Heinz (2017). [3+2] cycloadditions of n-protected ‘(s)-diazoproline’ with selected acetylenes. Heterocycles, 95(1):223-231.

Abstract

Acetylene carboxylates and an acetylene phosphonate reacted with N-protected (S)-2-(diazoacetyl)pyrrolidines ((S)-diazoprolines) to give optically active bis-heterocyclic pyrazole derivatives in a regioselective [3+2] cycloaddition. The reactions occurred at 60 °C in THF solution in the absence of a catalyst. However, diethyl ethynylphosphonate reacted significantly slower than the carboxylates. The obtained products were shown to exist in CDCl3 solution at room temperature as mixtures of rotamers. The reactions of diethyl ethynylphosphonate with a selected cyclic α-oxodiazo compound, i.e. 2-diazoacenaphthen-1-one, yielded a fused tricyclic pyrazole derivative.

Abstract

Acetylene carboxylates and an acetylene phosphonate reacted with N-protected (S)-2-(diazoacetyl)pyrrolidines ((S)-diazoprolines) to give optically active bis-heterocyclic pyrazole derivatives in a regioselective [3+2] cycloaddition. The reactions occurred at 60 °C in THF solution in the absence of a catalyst. However, diethyl ethynylphosphonate reacted significantly slower than the carboxylates. The obtained products were shown to exist in CDCl3 solution at room temperature as mixtures of rotamers. The reactions of diethyl ethynylphosphonate with a selected cyclic α-oxodiazo compound, i.e. 2-diazoacenaphthen-1-one, yielded a fused tricyclic pyrazole derivative.

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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:English
Date:2017
Deposited On:05 Aug 2016 09:17
Last Modified:24 Apr 2017 08:15
Publisher:Elsevier
ISSN:0385-5414
Funders:National Science Center (PL-Cracow) (Grant Maestro-3; Dec-2012/06/A/ST5/00219)
Publisher DOI:https://doi.org/10.3987/COM-16-S(S)7

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