Abstract
An efficient organocatalytic reaction using 1,3-nitro enynes with 4-hydroxycoumarin and 4-hydroxy-6-methyl-2-pyrone to afford pyrano-annulated scaffolds in high yield (up to 88% yield) and excellent stereoselectivities (up to >20:1 dr and >99% ee) is described. The reaction proceeded through sequential conjugate addition, allene formation, intramolecular oxa-Michael 6-endo-dig cyclization and DABCO-catalyzed olefin isomerization. A kinetic profile for isomerization was established. The mechanism for the organocascade reaction was proposed according to requisite computational and mechanistic experimental studies.
| Original language | English |
|---|---|
| Pages (from-to) | 3098-3101 |
| Number of pages | 4 |
| Journal | Organic Letters |
| Volume | 18 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - 2016 Jul 1 |
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ASJC Scopus subject areas
- Biochemistry
- Physical and Theoretical Chemistry
- Organic Chemistry
Cite this
Organocascade Synthesis of Annulated (Z)-2-Methylenepyrans : Nucleophilic Conjugate Addition of Hydroxycoumarins and Pyranone to Branched Nitro Enynes via Allene Formation/Oxa-Michael Cyclization/Alkene Isomerization Sequence. / Gurubrahamam, Ramani; Gao, Bing Fong; Chen, Yan Ming; Chan, Yu Te; Tsai, Ming-Kang; Chen, Kwunmin.
In: Organic Letters, Vol. 18, No. 13, 01.07.2016, p. 3098-3101.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Organocascade Synthesis of Annulated (Z)-2-Methylenepyrans
T2 - Nucleophilic Conjugate Addition of Hydroxycoumarins and Pyranone to Branched Nitro Enynes via Allene Formation/Oxa-Michael Cyclization/Alkene Isomerization Sequence
AU - Gurubrahamam, Ramani
AU - Gao, Bing Fong
AU - Chen, Yan Ming
AU - Chan, Yu Te
AU - Tsai, Ming-Kang
AU - Chen, Kwunmin
PY - 2016/7/1
Y1 - 2016/7/1
N2 - An efficient organocatalytic reaction using 1,3-nitro enynes with 4-hydroxycoumarin and 4-hydroxy-6-methyl-2-pyrone to afford pyrano-annulated scaffolds in high yield (up to 88% yield) and excellent stereoselectivities (up to >20:1 dr and >99% ee) is described. The reaction proceeded through sequential conjugate addition, allene formation, intramolecular oxa-Michael 6-endo-dig cyclization and DABCO-catalyzed olefin isomerization. A kinetic profile for isomerization was established. The mechanism for the organocascade reaction was proposed according to requisite computational and mechanistic experimental studies.
AB - An efficient organocatalytic reaction using 1,3-nitro enynes with 4-hydroxycoumarin and 4-hydroxy-6-methyl-2-pyrone to afford pyrano-annulated scaffolds in high yield (up to 88% yield) and excellent stereoselectivities (up to >20:1 dr and >99% ee) is described. The reaction proceeded through sequential conjugate addition, allene formation, intramolecular oxa-Michael 6-endo-dig cyclization and DABCO-catalyzed olefin isomerization. A kinetic profile for isomerization was established. The mechanism for the organocascade reaction was proposed according to requisite computational and mechanistic experimental studies.
UR - http://www.scopus.com/inward/record.url?scp=84977280240&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84977280240&partnerID=8YFLogxK
U2 - 10.1021/acs.orglett.6b01265
DO - 10.1021/acs.orglett.6b01265
M3 - Article
AN - SCOPUS:84977280240
VL - 18
SP - 3098
EP - 3101
JO - Organic Letters
JF - Organic Letters
SN - 1523-7060
IS - 13
ER -