2017年
Direct Access to N-Unprotected α- and/or β-Tetrasubstituted Amino Acid Esters via Direct Catalytic Mannich-Type Reactions Using N-Unprotected Trifluoromethyl Ketimines
Chemistry - A European Journal
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- 巻
- 23
- 号
- 67
- 開始ページ
- 17022
- 終了ページ
- 17028
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1002/chem.201703516
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Direct catalytic C−C bond-forming addition to N-unprotected ketimines is an efficient and straightforward method of synthesizing N-unprotected tetrasubstituted amines that eliminates prior protection/deprotection steps and allows facile transformation of the products. Despite its advantages, however, N-unprotected ketimines have difficulties in C−C bond-forming reactions, and only a limited number of reactions and substrates are reported compared with their N-protected counterparts. Herein we report that N-unprotected trifluoromethyl ketimines are effective for C−C bond-forming reactions using Mannich-type reactions as a model case. We demonstrate that Lewis acid catalysis was effective for promoting reactions with various N-unprotected trifluoromethyl ketimines, and thiourea organocatalysis was effective for promoting highly enantioselective reactions with various carbonyl nucleophiles, providing direct access to various N-unprotected α- and/or β-tetrasubstituted amino acid esters. Furthermore, direct construction of vicinal tetrasubstituted chiral carbon stereocenters was achieved for the first time in a highly enantio- and diastereoselective manner. These results demonstrate the potential of N-unprotected ketimines as substrates applicable to many other addition reactions.
- リンク情報
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- DOI
- https://doi.org/10.1002/chem.201703516
- PubMed
- https://www.ncbi.nlm.nih.gov/pubmed/28950035
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000418570000017&DestApp=WOS_CPL
- URL
- http://www.scopus.com/inward/record.url?eid=2-s2.0-85035772279&partnerID=MN8TOARS
- Scopus Citedby
- https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85035772279&origin=inward
- ID情報
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- DOI : 10.1002/chem.201703516
- ISSN : 0947-6539
- eISSN : 1521-3765
- ORCIDのPut Code : 54231878
- PubMed ID : 28950035
- SCOPUS ID : 85035772279
- Web of Science ID : WOS:000418570000017