Brønsted Acid-Catalyzed, Asymmetric Allenoate Claisen Reaction
An auxiliary-based protocol is described for an asymmetric allenoate Claisen rearrangement. Silicated tosic acid (10 mol %) was used as an inexpensive, user-friendly catalyst. Stereochemical analysis revealed a preferential attack at the si face of prostereogenic olefin. The amine auxiliary was read...
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| Published in: | Journal of organic chemistry |
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| Main Authors: | , , , , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
26-11-2024
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| Online Access: | Get full text |
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| Summary: | An auxiliary-based protocol is described for an asymmetric allenoate Claisen rearrangement. Silicated tosic acid (10 mol %) was used as an inexpensive, user-friendly catalyst. Stereochemical analysis revealed a preferential attack at the si face of prostereogenic olefin. The amine auxiliary was readily hydrolyzed and can be isolated from the reaction mixture (85-87% recovery). The resulting unsaturated β-keto esters were isolated in ≤99% yield and 98% ee. Diastereoselective examples provided a 96:4 syn:anti ratio of the resulting vicinal stereocenters.An auxiliary-based protocol is described for an asymmetric allenoate Claisen rearrangement. Silicated tosic acid (10 mol %) was used as an inexpensive, user-friendly catalyst. Stereochemical analysis revealed a preferential attack at the si face of prostereogenic olefin. The amine auxiliary was readily hydrolyzed and can be isolated from the reaction mixture (85-87% recovery). The resulting unsaturated β-keto esters were isolated in ≤99% yield and 98% ee. Diastereoselective examples provided a 96:4 syn:anti ratio of the resulting vicinal stereocenters. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0022-3263 1520-6904 1520-6904 |
| DOI: | 10.1021/acs.joc.4c02062 |