The Use of N-iPr-2,2'-bipyrrolidine Derivatives as Organocatalysts for Asymmetric Michael Additions
The recent rapid growth of organocatalysis has shown a new approach in organic chemistry and presents the obvious advantage in the avoidance of expensive and often toxic metals. Moreover, the organocatalysts are generally easier to make than standard catalytic reagents. Therefore, our labo...
| Main Authors: | , , |
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| Format: | Article |
| Language: | deu |
| Published: |
Swiss Chemical Society
2006-04-01
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| Series: | CHIMIA |
| Subjects: | |
| Online Access: | https://chimia.ch/chimia/article/view/4151 |
| Summary: | The recent rapid growth of organocatalysis has shown a new approach in organic chemistry and presents the obvious advantage in the avoidance of expensive and often toxic metals. Moreover, the organocatalysts are generally easier to make than standard catalytic reagents. Therefore, our
laboratory has synthesized N-alkyl-2,2'bipyrrolidine derivatives as a new class of organocatalysts and applied them to the asymmetric Michael addition of ketones and aldehydes to nitroolefins via an enamine intermediate. We have furthermore developed the first asymmetric Michael addition
of aldehydes to vinyl sulfones catalyzed with our diamines. The 1,4 adducts are obtained in good yields with enantioselectivities up to 80% ee. The determination of absolute configuration allowed us to postulate a Si,Si transition state model, as described previously for nitroolefins.
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| ISSN: | 0009-4293 2673-2424 |