| Autor: |
Tetsuhiro Nemoto, Kazuki Tsuruda, Mariko Yoshida, Masato Kono, Yasumasa Hamada |
| Předmět: |
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| Zdroj: |
Synthesis; 2015, Vol. 47 Issue 24, p3914-3924, 11p |
| Abstrakt: |
We have developed a novel method for synthesizing trisubstituted cyclopropane derivatives by a palladium-catalyzed intramolecular allylic alkylation of ƒ¿-aryl esters. By using ƒ¿-aryl ƒ¿-(methoxycarbonyl) ƒÁ-vinyl ƒÁ-lactones as substrates, decarboxylative formation of ƒÎ- allylpalladium(II) intermediates followed by an intramolecular allylic alkylation of the ester enolates proceeded in the presence of 5 mol% of a palladium catalyst, producing 1-aryl-1-(methoxycarbonyl)-2-vinylcyclopropanes in good to excellent yields and high diastereoselectivities. The relative configuration of the major isomer was determined by transforming the product into a known intermediate of milnacipran synthesis. When we extended our method to asymmetric catalysis, we obtained methyl (1S,2S)-1-phenyl-2-vinylcyclopropanecarboxylate in up to 55% ee by using (S)-[2Œ-(diphenylmethoxy)-1,1Œ-binaphthalen-2- yl](diphenyl)phosphine as a chiral monodentate phosphorus ligand. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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