An Intramolecular Wittig Approach toward Heteroarenes: Synthesis of Pyrazoles, Isoxazoles, and Chromenone-oximes

Pankaj V. Khairnar; Tsai Hui Lung; Yi Jung Lin; Chi Yi Wu; Srinivasa Rao Koppolu; Athukuri Edukondalu; Praneeth Karanam; Wenwei Lin

doi:10.1021/acs.orglett.9b01395

An Intramolecular Wittig Approach toward Heteroarenes: Synthesis of Pyrazoles, Isoxazoles, and Chromenone-oximes

Pankaj V. Khairnar, Tsai Hui Lung, Yi Jung Lin, Chi Yi Wu, Srinivasa Rao Koppolu, Athukuri Edukondalu, Praneeth Karanam, Wenwei Lin

Department of Chemistry

Research output: Contribution to journal › Article

3 Citations (Scopus)

Abstract

α-Halohydrazones/ketoximes are transformed into trisubstituted pyrazoles/disubstituted isoxazoles by treatment with phosphine, acyl chloride, and a base. Mechanistic investigations revealed the in situ formation of azo/nitroso olefin intermediates which underwent a tandem phospha-Michael/N- or O-acylation/intramolecular Wittig reaction to afford the heteroarenes in moderate to good yields. Further, proper functionalization of α-haloketoximes and a change of conditions allowed the chemoselective synthesis of chromenone-oximes as well as rearranged isoxazoles, thereby realizing a diversity-oriented synthesis.

Original language	English
Pages (from-to)	4219-4223
Number of pages	5
Journal	Organic Letters
Volume	21
Issue number	11
DOIs	https://doi.org/10.1021/acs.orglett.9b01395
Publication status	Published - 2019 Jun 7

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ASJC Scopus subject areas

Biochemistry
Physical and Theoretical Chemistry
Organic Chemistry

Cite this

Khairnar, P. V., Lung, T. H., Lin, Y. J., Wu, C. Y., Koppolu, S. R., Edukondalu, A., Karanam, P., & Lin, W. (2019). An Intramolecular Wittig Approach toward Heteroarenes: Synthesis of Pyrazoles, Isoxazoles, and Chromenone-oximes. Organic Letters, 21(11), 4219-4223. https://doi.org/10.1021/acs.orglett.9b01395

An Intramolecular Wittig Approach toward Heteroarenes : Synthesis of Pyrazoles, Isoxazoles, and Chromenone-oximes. / Khairnar, Pankaj V.; Lung, Tsai Hui; Lin, Yi Jung; Wu, Chi Yi; Koppolu, Srinivasa Rao; Edukondalu, Athukuri; Karanam, Praneeth; Lin, Wenwei.

In: Organic Letters, Vol. 21, No. 11, 07.06.2019, p. 4219-4223.

Research output: Contribution to journal › Article

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10.1021/acs.orglett.9b01395