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 | |
| Publication status | Published - 2019 Jun 7 |
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ASJC Scopus subject areas
- Biochemistry
- Physical and Theoretical Chemistry
- Organic Chemistry
Cite this
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, Wen-Wei.
In: Organic Letters, Vol. 21, No. 11, 07.06.2019, p. 4219-4223.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An Intramolecular Wittig Approach toward Heteroarenes
T2 - Synthesis of Pyrazoles, Isoxazoles, and Chromenone-oximes
AU - Khairnar, Pankaj V.
AU - Lung, Tsai Hui
AU - Lin, Yi Jung
AU - Wu, Chi Yi
AU - Koppolu, Srinivasa Rao
AU - Edukondalu, Athukuri
AU - Karanam, Praneeth
AU - Lin, Wen-Wei
PY - 2019/6/7
Y1 - 2019/6/7
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85067025370&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85067025370&partnerID=8YFLogxK
U2 - 10.1021/acs.orglett.9b01395
DO - 10.1021/acs.orglett.9b01395
M3 - Article
C2 - 31117709
AN - SCOPUS:85067025370
VL - 21
SP - 4219
EP - 4223
JO - Organic Letters
JF - Organic Letters
SN - 1523-7060
IS - 11
ER -