Reaction of α,β-Unsaturated Fischer Carbene Complexes with Allyl Alkoxide
| Autor: | Motokazu Uemura, Masaru Furusyo, Kazuya Uchida, Ken Kamikawa, Atsushi Tachibana, Yasunori Shimizu |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
CHROMIUM COMPLEX Base (chemistry) Stereochemistry Transition metal carbene complex Organic Chemistry chemistry.chemical_element General Medicine Planar chirality Biochemistry Medicinal chemistry chemistry.chemical_compound Chromium chemistry Reaction sequence Drug Discovery Alkoxide Enantiomeric excess Carbene |
| Zdroj: | ChemInform. 37 |
| ISSN: | 1522-2667 0931-7597 |
| DOI: | 10.1002/chin.200622085 |
| Popis: | Optically enriched homo-binuclear Fischer chromium carbene complexes with planar chiral arene chromium complexes gave α-allyl β-arylpropionates up to 97% ee by reaction with allyl alkoxide and subsequent photo-oxidative demetalation. The chiral hetero-binuclear tungsten carbene complexes afforded anti α-allyl β-hydroxy β-arylpropionates as a major product up to 92/8 dr by the same reaction sequence. High diastereoselectivity in these reactions is contributed to the planar chirality of the arene chromium complex, even though the reaction was carried out under vigorous basic media. The reaction products, α-allyl β-arylpropionates were derived by 1,3-M(CO)5 shift and subsequent [3,3]-sigmatropic rearrangement. Also, the corresponding chromium-uncomplexed α,β-unsaturated Fischer carbene complexes afforded α-allyl β-arylpropionates under the same conditions. Formation of β-allyl β-arylpropionates via 1,2-M(CO)5 shift followed by [3,4]-sigmatropic rearrangement was not observed in both reactions of chromium-coordinated and the corresponding chromium-uncoordinated α,β-unsaturated Fischer carbene complexes with allyl alkoxide in the presence of base. |
| Databáze: | OpenAIRE |
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