| Publication Type |
Journal Article |
| Title |
Ring-Expansion Reaction of Isatins with Ethyl Diazoacetate Catalyzed by Dirhodium(II)/DBU Metal-Organic System: En Route to Viridicatin Alkaloids |
| Authors |
Roberta Paterna Vânia André M. Teresa Duarte Luis F. Veiros Nuno R. Candeias Pedro M. P. Gois |
| Groups |
BIOMOL IOARC |
| Journal |
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY |
| Year |
2013 |
| Month |
October |
| Volume |
2013 |
| Number |
28 |
| Pages |
6280-6290 |
| Abstract |
We present here the NHC-dirhodium(II)/DBU-catalyzed ring expansion reaction of isatins with ethyl diazoacetate. This new one-pot protocol yields the ethyl 3-hydroxy-2(1H)-oxoquinoline-4-carboxylate core, regioselectively and in good to excellent yields. A DFT mechanistic study indicates metallocarbene formation between the 3-hydroxyindole-diazo intermediate and the dirhodium(II) complex to be the rate-limiting step of the reaction. The synthesized ethyl 3-hydroxy-2(1H)-oxoquinoline-4-carboxylate core could be readily converted to viridicatin alkaloids, in yields up to 80\% by a microwave-assisted Suzuki-Miyaura cross coupling of the 3-hydroxy-4-bromoquinolin-2(1H)-one with arylboronic acid. |
| DOI |
http://dx.doi.org/10.1002/ejoc.201300796 |
| ISBN |
|
| Publisher |
|
| Book Title |
|
| ISSN |
1434-193X |
| EISSN |
1099-0690 |
| Conference Name |
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| Bibtex ID |
ISI:000324932400013 |
| Observations |
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