Chiral Anion Directed Asymmetric Carbocation-Catalyzed Diels-Alder Reactions
2016 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 9, 1708-1713 p.Article in journal (Refereed) PublishedText
In recent years the carbocation has re-emerged as a highly efficient Lewis acid catalyst for a variety of organic transformations. However, the goal of asymmetric carbocation catalysis has so far been out of reach mainly as a result of difficulties associated with the preparation of stable chiral carbocations. Here, we describe developments towards asymmetric carbocation catalysis based on the concept of chiral-anion-directed catalysis. Chiral tritylium salts can be conveniently prepared in situ by mixing trityl chloride derivatives with chiral phosphonate, phosphoramide, bis(sulfonyl) amide, and bis(sulfuryl) amide silver or sodium salts. It is shown that the bis(sulfuryl) amide/tritylium ion salt catalyzes the Diels-Alder reaction with an up to 53 % enantiomeric excess.
Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2016. no 9, 1708-1713 p.
Synthetic methods, Asymmetric catalysis, Cycloaddition, Carbocations, Trityl ion
IdentifiersURN: urn:nbn:se:kth:diva-186566DOI: 10.1002/ejoc.201501621ISI: 000374149600012ScopusID: 2-s2.0-84959310716OAI: oai:DiVA.org:kth-186566DiVA: diva2:927996
QC 201605132016-05-132016-05-132016-05-13Bibliographically approved