Enantioselective Polyene Cyclization Catalyzed by a Chiral Brønsted Acid
The first enantioselective polyene cyclization initiated by a BINOL‐derived chiral N‐phosphoramide (NPA) catalyzed protonation of an imine is described. The ion‐pair formed between the iminium ion and chiral counter anion of the NPA plays an important role for controlling the stereochemistry of the...
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Published in | Angewandte Chemie International Edition Vol. 57; no. 8; pp. 2115 - 2119 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
WEINHEIM
Wiley
19.02.2018
Wiley Subscription Services, Inc |
Edition | International ed. in English |
Subjects | |
Online Access | Get full text |
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Summary: | The first enantioselective polyene cyclization initiated by a BINOL‐derived chiral N‐phosphoramide (NPA) catalyzed protonation of an imine is described. The ion‐pair formed between the iminium ion and chiral counter anion of the NPA plays an important role for controlling the stereochemistry of the overall transformation. This strategy offers a highly efficient approach to fused tricyclic frameworks containing three contiguous stereocenters, which are widely found in natural products. In addition, the first catalytic asymmetric total synthesis of (−)‐ferruginol was accomplished with an NPA catalyzed enantioselective polyene cyclization, as the key step for the construction of the tricyclic core, with excellent yield and enantioselectivity.
Pair up: The first enantioselective polyene cyclization initiated by a BINOL‐derived chiral N‐phosphoramide (NPA)‐catalyzed protonation of an imine is described. The ion pair formed between the iminium ion and chiral counter anion of the NPA plays an important role in controlling the stereochemistry of the overall transformation. This strategy offers a highly efficient approach to fused tricyclic frameworks containing three contiguous stereocenters, and was applied to the first catalytic asymmetric total synthesis of (−)‐ferruginol. Ts=4‐toluenesulfonyl. |
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Bibliography: | Dedicated to Professor E. J. Corey on the occasion of his 90th birthday These authors contributed equally to this work. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1433-7851 1521-3773 |
DOI: | 10.1002/anie.201711603 |